Study on Tool wear mechanism under Cryogenic CO2-Assisted Minimum Quantity Lubrication Technology

Study on Tool wear mechanism under Cryogenic CO2-Assisted Minimum Quantity Lubrication Technology | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Research Article Study on Tool wear mechanism under Cryogenic CO2-Assisted Minimum Quantity Lubrication Technology Lin Cheng, Tian Qiu, Shizhan Huang, Hong Xie, Chao Liu, Yousheng Li, and 7 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-1734237/v1 This work is licensed under a CC BY 4.0 License Status: Published Journal Publication published 28 Feb, 2023 Read the published version in The International Journal of Advanced Manufacturing Technology → Version 1 posted 5 You are reading this latest preprint version Abstract Cryogenic CO 2 -assisted minimum quantity lubrication milling technology is a green processing technology with broad application prospects. Aiming at the problem of tool wear in the application of cryogenic CO 2 cooling assisted minimum quantity lubrication in difficult-to-machine materials and the influence of relevant parameters on tool wear, this study used coated cemented carbide tools to perform milling experiments under cryogenic CO 2 -assisted minimum quantity lubrication technology conditions. The micromorphology of the tool rake face and chip was observed, and the energy spectrum of the tool chip contact area was analyzed. The results showed that reducing CO 2 temperature and increasing the oil flow of minimum quantity lubrication can improve the tool wear. The tool wear mechanisms under cryogenic CO 2 -assisted minimum quantity lubrication were mainly abrasive wear, diffusion wear, and oxidation wear. The chip sawtooth degree of the optimal parameter group was more conducive to chip breaking than that of dry cutting and wet cutting groups. The temperature of the tool-chip contact area is an important factor affecting tool wear, the higher the temperature, the faster the tool wear. At the same time, it is verified that cryogenic CO 2 -assisted minimum quantity lubrication technology can replace cutting fluid in hard-to-machine materials under certain conditions. cryogenic CO2 minimum quantity lubrication tool wear mechanism serrated chip high speed milling Figures Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 Figure 7 Figure 8 Figure 9 Figure 10 Figure 11 Figure 12 Figure 13 Figure 14 Figure 15 Figure 16 Figure 17 Figure 18 Figure 19 Figure 20 Figure 21 Figure 22 Figure 23 Figure 24 Figure 25 Figure 26 1 Introduction The use of cutting fluids is widely in machining. However, conventional cutting fluids cooling has high consumption and production costs[ 1 – 3 ], causes serious environmental pollution, and harms the health of operators[ 4 – 6 ]. Green cutting technology is developed to solve these problems. At present, green cutting technology mainly includes dry cutting, minimum quantity lubrication (MQL), cryogenic cutting, cryogenic minimum quantity lubrication, and so on[ 7 , 8 ]. In the machining of difficult-to-machine materials, dry cutting has the lowest cost, but it has high cutting temperature and cutting force[ 9 , 10 ]. MQL can be applied to the machining of aluminum alloy, stainless steel, and carbon structural steel[ 11 – 13 ]. However, it is prone to insufficient cooling, and the cooling effect is poor when the cutting temperature is high[ 14 – 16 ]. Cryogenic cutting technology includes cryogenic CO 2 cooling, cryogenic nitrogen cooling, cryogenic air cooling, etc. Quite a few examine have researched that cryogenic cutting technology is mainly used in the processing of titanium alloy, magnesium alloy, superalloy, and high-strength steel[ 17 – 19 ], which can improve the tool life and processing quality[ 20 ]. However, the lubrication effect of cryogenic cutting is unfavorable[ 21 , 22 ]. Previous studies of the machining of difficult-to-machine materials have presented that minimum quantity lubrication technology at low temperature has significant advantages in improving the processing quality and tool life[ 23 – 25 ]. Cryogenic minimum quantity lubrication technology is a method combining cryogenic cutting and minimum quantity lubrication, which includes cryogenic air-assisted MQL, cryogenic nitrogen-assisted MQL, cryogenic CO 2 -assisted MQL, and so on. In the machining of difficult-to-machine materials, although the cryogenic air-assisted MQL can reduce the tool wear and improve the tool life, the cooling effect is limited[ 21 ]. Cryogenic nitrogen-assisted MQL can reduce the cutting force and improve processing quality, but the effect of reducing tool wear is less impressive[ 26 , 27 ]. However, previous studies of the cryogenic CO 2 -assisted MQL have emphasized favorable advantages in reducing tool wear and improving tool life[ 28 – 30 ]. In addition, cryogenic CO 2 -assisted MQL has the advantages of low cost, non-toxic, and non-pollution, and has widespread use in practical production. The use of cryogenic CO 2 is beneficial to the realization of carbon neutralization and peak target to a certain extent[ 30 ]. However, cryogenic CO 2 -assisted MQL is a green cutting technology that is more likely to replace cutting fluid, and there are a few pieces of research in the field. In this study, the effect of cryogenic CO 2 temperature and minimum quantity lubrication oil flow in milling experiments of difficult-to-machine materials was examined. In regards to this study, the tool wear form, wear mechanism, and chip morphology in the cryogenic CO 2 -assisted MQL were studied, compared with those in the wet and dry cutting. This work provided a theoretical basis for the application of cryogenic CO 2 -assisted MQL in the processing of difficult-to-machine materials. 2 Materials And Methods In this study, N87 alloy steel was used as the workpiece, which is a typical difficult-to-machine material. The main chemical composition of N87 alloy steel was presented in Table 1, and the mechanical and physical properties of N87 was shown in Table 2. The APKT1604PDTR KC725M cemented carbide tool and mircolube cryo 75 minimum quantity lubrication oil were selected for the milling experiments, cutting tool geometric parameters and coating structure were shown in Fig. 1. All the milling experiments were carried out in the VMC-1600 CNC of Shenyang, and the cutting parameter was shown in Table 3. Table 1 Chemical composition of N87 (wt%) Element C Si Mn Cr Ni Co W Mo V Nb N Fe Mass fraction 0.08 ～ 0.13 ≤0.1 0.35～ 0.65 10.00～ 12.00 0.30～ 0.70 2.5 ～ 3.5 2.40～ 3.00 0.10～ 0.40 0.15～ 0.25 0.05～ 0.12 0.01 ～ 0.035 Others Table 2 Mechanical and physical properties of N87 Yield strength (MPa) Ultimate tensile strength (MPa) Elongation (%) Shrinkage (%) Hardness (HB) 620 885 15 45 321 Table 3 Cutting parameter Cutting speed (m/min) Feed rate (mm/rev) Cutting depth (mm) Cutting width (mm) Cutting length (m) Cutting parameter 158 0.12 1 21 10.5 As shown in Table 4, different CO 2 temperatures and minimum quantity lubrication oil flow were designed in the milling experiments. In addition, the experiments of dry cutting and wet cutting were carried out, which have been seen as comparative milling experiments. The cutting process was shown in Fig. 2. The wear of the collected tools under different cooling conditions was observed and compared. In this work, Kroll reagent and alcohol ultrasonic cleaning methods were used to remove the adhesive chips and other impurities on the tool. The tool wear and chips were observed by scanning electron microscope (SEM), and the elemental analysis of the tool surface was analyzed by energy dispersive spectrometer(EDS). Table 4 Design of experiments Experimental parameters Lubrication methods Oil flow (ml/h) Temperature (℃) Group Dry cutting 1 Wet cutting 2 Cryogenic CO 2 -assisted MQL 60 -10 3 60 -30 4 60 -50 5 0 -50 6 40 -50 7 80 -50 8 3 Results 3.1 Tool wear form In Fig. 3, the wear form of the rake face under dry cutting was shown, and the overall wear was serious. Due to the high cutting temperature and poor lubrication conditions, the coating of the main cutting edge was peeled off seriously, and micro-chipping occured in the fillet area of the tool tip. As seen in Fig. 4, the wear form of rake face under wet cutting cooling was normal wear of cutting edge and peeling of the coating. This benefited from the low temperature and favorable lubrication of the cutting area. Figures 5-7 showed the wear form of rake face under cryogenic CO 2 -assisted MQL experiments when oil flow was kept unchanged at 60 ml/h and cryogenic CO 2 temperature was set to -10℃, -30℃ and -50℃. As shown in Fig. 5, the main cutting edge of the tool under -10 ℃ had a large area of chipping, and the coating of the minor cutting edge peeled off seriously. Figure 6 clearly showed that the micro-chipping and crater wear appeared on the main cutting edge of the tool under -30℃, and the serious coating material damage appeared in the fillet area of the tool tip. In addition, when the CO 2 temperature was -50℃, the main cutting edge of the tool was in good condition and the coating was worn evenly, as shown in Fig. 7. It can be found that the tool wear decreases gradually with the decrease of cryogenic CO 2 temperature when comparing the tool wear forms of three experimental groups. When the cryogenic CO 2 temperature was -50℃, the tool wear was lighter than that of -10℃ and -30℃. The reason is that after the temperature is reduced, the cryogenic CO 2 carrier can make the oil mist reach the cutting area stably, which can make the lubrication conditions well. In addition, when the cryogenic CO 2 temperature was -50℃, the cooling effect was favorable. The wear form of the rake face under -10℃ and -30℃ was more serious than that during dry cutting, because the lubricating oil cannot get into the cutting area steadily which results in instability of the cutting state and serious tool wear, and the cooling effect was unfavorable. Figures 7-10 showed the wear form of rake faces under cryogenic CO 2 -assisted MQL experiments when cryogenic CO 2 temperature was kept unchanged at -50℃ and oil flow was set to 0 ml/h, 40 ml/h, 60 ml/h and 80 ml/h. As seen in Fig. 8, the crater wear and coating peeling appeared on the main cutting edge of the tool when the oil flow was 0 ml/h. In addition, the local coating peeling occurred on the minor cutting edge. As illustrated in Fig. 9, although the tool crater wear was reduced, the coating peeling was still uneven and also occurred on the minor cutting edge. However, when the oil flow is 60 ml/h, the main cutting edge was worn evenly without abnormal wear, as shown in Fig. 7. In Fig. 8, the wear form of the rake face when oil flow was 80 ml/h was shown. Although the wear of the main cutting edge was uniform, the coating peeling was more serious than that when oil flow was 60 ml/h and the small range of coating peeling occurred on the minor cutting edge. Compared with the tool wear forms of the four experiment groups, the tool wear was generally reduced with the increase of minimum quantity lubrication oil flow. The main reason for the improvement of tool wear was that the lubrication conditions in the cutting area become better with the increase in oil flow. Thus, the friction between the tool and workpiece or chip was reduced, and the tool wear was improved. However, when the lubricating oil flow was too large, the particles of oil mist will increase, making it more difficult for oil mist to enter the cutting area. Consequently, the lubrication effect decreased and the tool wear increased. Based on the above analysis, it indicates that the experimental group which oil flow is 60 ml/h and the cryogenic CO 2 temperature is -50℃ has the lightest tool wear and the experimental parameters are optimal. 3.2 Tool wear mechanism 3.2.1 Adhesive wear Figures 11-13 showed the comparison diagram of the rake face before and after tool etching in the experiments of dry cutting, wet cutting, and the optimal parameter array of cryogenic CO 2 -assisted MQL. Through the comparison, the chip adhesion and adhesive wear area can be clearly seen. In the cutting process, the high cutting temperature and high pressure will be produced in the tool-chip contact area zone, resulting in cold welding, which makes the workpiece material easy to bond to the cutting edge of the tool[31,32]. The adhesion workpiece material fell off under intermittent mechanical impact load during the high-speed milling, and the coating material will be taken away, which results in adhesive wear on the tool surface. With the progress of cutting, the bonding and peeling process of workpiece materials were repeated, resulting in the aggravation of adhesive wear. As shown in Fig. 11, the adhesive wear of the tool during dry cutting was serious on the main cutting edge and the fillet area of the tool tip, and also occurred on the minor cutting edge. In addition, the damage caused by bonding and tearing on the fillet area of the tool tip was also shown in Fig. 11. This was mainly due to the poor cooling and lubrication condition, which leads to the high temperature under alternating mechanical stress and thermal stress. In this case, the bonding of workpiece material was more serious under high temperature and pressure, and the adhesion layer was easier to fall off during processing due to the high friction in the tool-chip contact area, resulting in serious adhesive wear. As seen in Fig. 12, the adhesive wear of the tool was relatively light under wet cutting cooling and the chip adhesive area was small and mainly occurred on the main cutting edge. This benefitted from the favorable cooling and lubrication condition, and the low temperature and friction in the tool-chip contact area zone. Figure 13 showed the tool adhesive wear of the optimal parameter array (oil flow 60 ml/h, CO 2 temperature -50℃), it can be found that the chip adhesive area was small and mainly occurred on the main cutting edge. The area and degree of adhesive wear was better than that of dry cutting tool, and more uniform than that of wet cutting tool. The reason was that the extremely low temperature and the phase transformation of liquid CO 2 when it reached the tool-chip contact area zone can effectively reduce the cutting temperature, maintain the hardness of tool surface, and reduce the impact of the adhesive layer falling off on the tool coating. In addition, under the protection of cryogenic CO 2 at temperature -50℃, the lubricating oil mist can stably and effectively enter the tool-chip contact area zone, which can reduce the cutting force and the adhesive wear of the tool. 3.2.2 Diffusion wear The tool and the workpiece are always in contact during the cutting process, and some alloy elements in the workpiece material diffuse into the tool under the action of high temperature. At the same time, some elements in the tool material will also diffuse into the workpiece material to form mutual diffusion[33,34]. The diffusion behavior of elements can be described by Fick's law, as shown in Eqs. (1)-(2). This mutual diffusion will reduce the strength of the tool to a certain extent and accelerate the wear of the tool[32]. However, the tool temperature is relatively not large because of the intermittent contact of milling[35], and the cutting time is relatively short in this experiment, so the element diffusion mainly occurs on the tool surface. Where is the flux, ,, are diffusion coefficient, concentration of diffusing species and time. Figure 14 showed the energy spectrum analysis of the main cutting edge in the experimental group of dry cutting, wet cutting, and optimal parameters experimental group (oil flow 60 ml/h, CO 2 , temperature -50℃). It can be seen from the figure that in addition to the elements C, N, Al, Ti, and W contained in the tool itself, there were also alloy elements such as Fe, Cr, Ni and Si contained in the workpiece material, which showed that the alloy elements in the workpiece material diffuse into the tool. The Fe, Ni, and Co were the congeners, and the diffusion of Ni, Fe, and Cr from the workpiece to the tool was because of the affinity for Co[36,37]. Figure 15 showed the mass percentage of Fe and Cr elements in the local area of the main cutting edge in 8 groups of experiments. It can be found from Fig. 15 that during dry cutting, due to poor cooling and lubrication, the diffusion of Fe and Cr elements was more serious, and the wet cutting experimental group had a better effect in controlling diffusion wear. In addition, the diffusion law of Fe and Cr in other groups was not obvious, and there was a certain element diffusion. Figure 16 was the element distribution diagram of two typical elements Fe and Cr diffused from the workpiece material to the tool. It can be found that the alloy elements such as Fe and Cr diffused from the workpiece material to the tool were relatively enriched in the wear area, indicating that the diffusion wear mainly occurred in the contact and wear area between the tool and the workpiece. There was little difference in the diffusion distribution of elements in the three groups of experiments, and the main difference was still in proportion. Due to the diffusion of elements in the workpiece material, the surface strength of the tool was reduced. In the cutting process, the tool surface with reduced strength was gradually worn, resulting in repeated element diffusion and wear. 3.2.3 Oxidation wear Oxidation wear refers to the chemical reaction between some elements in the tool material and oxygen in the air under the high temperature in the cutting area, resulting in oxides with low strength and hardness. With the progress of cutting, these oxides are taken away by the workpiece and chips, forming wear on the tool surface[38,39]. The mass percentage of the O element on the rake face of the tool in 8 groups of experiments were shown in Fig. 17. It can be found that the mass percentage of the O element was large, indicating that the tool surface was oxidized during cutting. Figure 18 showed the distribution of the O element, it can be seen that the O element was relatively enriched on the tool wear area. By analyzing the mass percentage and distribution of the O element, it can be seen obviously that the optimal parameter array of cryogenic CO 2 -assisted MQL had the best effect on the control of tool oxidation wear. The Co element and WC in the tool substrate material and Ti and Al element in the tool coating reacted with oxygen in the high temperature condition[40]. This oxide was the mixture of Al 2 O 3 , titanium dioxide, and others, which made the tool wear more serious in the process of repeated oxidation and wear. 3.2.3 Oxidation wear Oxidation wear refers to the chemical reaction between some elements in the tool material and oxygen in the air under the high temperature in the cutting area, resulting in oxides with low strength and hardness. With the progress of cutting, these oxides are taken away by the workpiece and chips, forming wear on the tool surface[38,39]. The mass percentage of the O element on the rake face of the tool in 8 groups of experiments were shown in Fig. 17. It can be found that the mass percentage of the O element was large, indicating that the tool surface was oxidized during cutting. Figure 18 showed the distribution of the O element, it can be seen that the O element was relatively enriched on the tool wear area. By analyzing the mass percentage and distribution of the O element, it can be seen obviously that the optimal parameter array of cryogenic CO 2 -assisted MQL had the best effect on the control of tool oxidation wear. The Co element and WC in the tool substrate material and Ti and Al element in the tool coating reacted with oxygen in the high temperature condition[40]. This oxide was the mixture of Al 2 O 3 , titanium dioxide, and others, which made the tool wear more serious in the process of repeated oxidation and wear. As shown in Fig. 23, the serrated degree and frequency of dry cutting, wet cutting, and the optimal parameter array were compared. It can be clearly seen that the serrated degree at 5mm and 10mm of the optimal parameter array was the largest, the sawtooth generation frequency of the optimal parameter array was similar to that of the wet cutting and far lower than that of dry cutting at 5mm, and it was the lowest at 10mm. The reason was that the excellent cooling and lubrication conditions make the lower temperature of the cutting area, which led to less plastic deformation region and more fracture region, and resulted in high serrated degree and low frequency[41,44]. And the cutting process was relatively stable [45]. Table 5 Analysis table of serrated degree at 5mm Experience group Average sawtooth spacing (mm） Average addendum height（mm） Average root height (mm） Serrated degree Frequency (kHz) Experiment 5 0.166 0.155 0.082 0.471 7.397 Dry cutting 0.125 0.121 0.078 0.355 11.201 Wet cutting 0.180 0.124 0.080 0.355 6.513 Table 6 Analysis table of serrated degree at 10mm Experience group Average sawtooth spacing (mm） Average addendum height（mm） Average root height (mm） Serrated degree Frequency (kHz) Experiment 5 0.175 0.202 0.125 0.381 10.536 Dry cutting 0.161 0.199 0.129 0.3 12.778 Wet cutting 0.147 0.196 0.134 0.316 13.015 In the secondary deformation zone, a lot of heat was generated due to the adhesion and friction between the chip and the rake face under high pressure, so the temperature of the second deformation zone was high. And the flow stress of the chip materials was decreased because of the thermal softening effect, which resulted in plastic deformation of the chip material near the rake face. Therefore, the state of the second deformation zone can largely reflect the temperature during cutting and the quality of cooling and lubrication, and the width of the second deformation zone was described by , as shown in Fig. 20. The of the three experiments was measured and shown in Fig. 24. It can be found that the of dry cutting at 5mm and 10mm was the largest, it was because of the high temperature during the cutting without the cooling and lubrication, and the flow stress was decreased. It meant that the friction in the second deformation zone was very large, resulting in serious tool wear as shown in Fig. 11. In addition, it can be clearly seen that the of the optimal parameter array at 5mm and 10mm was similar to that of the wet cutting and far lower than that of dry cutting. This indicated that the cutting fluid and cryogenic CO 2 can exchange heat well, and reduce the temperature rise in the second deformation area. In addition, the good lubrication conditions made the friction coefficient and friction force of the tool-chip contact area decrease, and the temperature of tool-chip contact area decreased relatively. Therefore, cutting fluid and cryogenic CO 2 -assisted MQL can improve the adhesion and friction between chip and the tool rake face, which was beneficial to improve tool wear. And it can also found that the cooling and lubrication condition of cryogenic CO 2 -assisted MQL is similar to that of cutting fluid, and the feasibility of the machining application of cryogenic CO 2 -assisted MQL is proved. The chip thickness of the three experiments was similar at 5mm, and the optimal parameter array of cryogenic CO 2 -assisted MQL at 10mm was the smallest. With the increase of the serrated degree, the chip thickness decreased. At the same time, it was conducive to the separation of chips and played a certain role in improving tool wear. Microhardness analysis was carried out with a force of 300gf on the non-free surface of chips obtained from the three groups of experiments, and the sampling points were shown in Fig. 25. As shown in Fig. 26, the non-free surface vickers hardness of dry cutting and wet cutting were similar. However, the hardness of the optimal parameter array of cryogenic CO 2 -assisted MQL was the highest. The reason was that during the process of cryogenic CO 2 -assisted MQL, cryogenic CO 2 increased the surface hardness of workpiece materials to a certain extent. When the cryogenic CO 2 temperature was low, the protection effect of cryogenic CO 2 on oil mist was unfavorable. It led to an increase in workpiece surface hardness and poor lubrication, which speeded up the tool wear. However, when the cryogenic CO 2 temperature met the requirements and the oil flow was appropriate, the protection effect of cryogenic CO 2 on oil mist was superior, which made the lubrication effect of the processing area better. Furthermore, the adverse effect on tool wear by the increase of workpiece surface hardness was reduced. 4 Conclusion This study based on the cryogenic CO 2 -assisted MQL, researched the influence mechanism of CO 2 temperature and oil flow on tool wear in the processing of difficult-to-machine materials, analyzed the tool wear mechanism and chip-morphology, and drew the following conclusions. (1) Under the condition of cryogenic CO 2 -assisted MQL, the lower the CO 2 temperature is, the better the improvement effect of tool wear, and there is an optimal value of oil flow. In addition, the lower the temperature of the CO 2 carrier is, the better the protective effect of the oil mist, so that the oil mist can reach the cutting area stably and effectively. Too small oil flow of MQL will lead to oil mist unable to meet the lubrication requirements. Excessive oil flow will lead to the enlargement of oil mist particles, resulting in unfavorable capillary permeation and accessibility of oil mist. (2) Tool wear is mainly adhesive wear, diffusion wear and oxidation wear, and so on. Among the dry cutting, wet cutting, and the optimal parameter array of cryogenic CO 2 -assisted MQL, wet cutting has a better control effect on tool diffusion wear, cryogenic CO 2 -assisted MQL has a better control effect on tool adhesive wear and oxidation wear. (3) The chip of cryogenic CO 2 -assisted MQL is the serrated chip. Compared with dry cutting and wet cutting, the optimal parameter array of cryogenic CO 2 -assisted MQL has a greater degree of the serrated chip, lower frequency, smaller width of the second deformation zone () and smaller thickness, which are conducive to chip breaking and beneficial to improve tool wear. Cryogenic CO 2 increases the surface hardness of the workpiece, but its adverse effect on tool wear can be effectively restrained under appropriate cryogenic CO 2 -assisted MQL. (4) The temperature of the tool-chip contact area is an important factor affecting tool wear. The higher cutting temperature accelerates the progress of adhesive wear, diffusion wear, and oxidation wear, which makes the coating material on the tool surface fall off quickly, forming crater wear, edge collapse, etc, and finally leads to the tool failure. In addition, the higher temperature leads to the high frequency and small serrated degree of chips, larger width of the second deformation zone () and increases the hardness of the non-free surface of the chip which speeds up the wear of the tool. Declarations Acknowledgements This work is supported by the Natural Science Foundation of Fujian Province (No. 2020J01066) and the Integration Project of Industry and Research of Fujian Province (No. 2020H6014). Funding This work is supported by the Natural Science Foundation of Fujian Province (No. 2020J01066) and the Integration Project of Industry and Research of Fujian Province (No. 2020H6014). Competing Interests The authors declare that they have no competing interests. Ethics approval Not applicable. Consent to Participate All authors agree to participate in this study. Consent to Publish All authors agree to publish this paper. Authors Contributions Feng Jiang provided ideas and guidance for the paper, Lin Cheng collected and analysed the date, and wrote the paper. Tian Qiu and Shizhan Huang helped collected and analyze the data. Hong Xie and Yan Shui provided experimental support. Chao Liu, Yousheng Li, Liangliang Lin and Zhiyang Xiang provided guidance and advice. Fuzeng Wang, Xian Wu and Lan Yan provided constructive suggestions on the structure and some contents of the paper. References Amiril S A S, Rahim E A, Syahrullail S (2017) A review on ionic liquids as sustainable lubricants in manufacturing and engineering: recent research, performance, and applications. Journal of Cleaner Production, 168:1571-1589. https://doi.org/10.1016/j.jclepro.2017.03.197 Gajrani K K, Suvin P S, Kailas S V, Sankar M R (2019) Hard machining performance of indigenously developed green cutting fluid using flood cooling and minimum quantity cutting fluid. Journal of Cleaner Production, 206:108-123. https://doi.org/10.1016/j.jclepro.2018.09.178 Astakhov V P, (2008) Ecological machining: near-dry machining. Machining: Fundamentals and Recent Advances. Springer London, London, pp 195-223. Lawal S A, Choudhury I A, Nukman Y (2012) Application of vegetable oil-based metalworking fluids in machining ferrous metals-a review. International Journal of Machine Tools and Manufacture, 52(1):1-12. https://doi.org/10.1016/j.ijmachtools.2011.09.003 Hannu T, Suuronen K, Aalto-Korte K, Alanko K, Luukkonen R, Järvelä M, Jolanki R, Jaakkola M S (2013) Occupational respiratory and skin diseases among finnish machinists: findings of a large clinical study. International Archives of Occupational and Environmental Health, 86(2):189-197. https://doi.org/10.1007/s00420-012-0754-8 Tan X C, Liu F, Cao H J, Zhang H (2002) A decision-making framework model of cutting fluid selection for green manufacturing and a case study, 129(1-3): 467-470. https://doi.org/10.1016/s0924-0136(02)00614-3 Liu Y, Li X J, Qu P X (2012) Research development and application of green cutting technology. Applied Mechanics and Materials, 160:82-86. https://doi.org/10.4028/www.scientific.net/ AMM.160.82 Cai C, Liang X, An Q, Tao Z, Ming W, Chen M (2021) Cooling/lubrication performance of dry and supercritical CO 2 -based minimum quantity lubrication in peripheral milling Ti-6Al-4V. International Journal of Precision Engineering and Manufacturing-Green Technology, 8(2):405-421. https://doi.org/10.1007/s40684-020-00194-7 Dong L, Li C, Zhou F, Bai X, Gao W, Duan Z, Li X, Lv X, Zhang F (2021) Temperature of the 45 steel in the minimum quantity lubricant milling with different biolubricants. The International Journal of Advanced Manufacturing Technology, 113(9-10):2779-2790. https://doi.org/10.1007/s00170-021-06708-0 Jamil M, Zhao W, He N, Gupta M K, Sarikaya M, Khan A M, R S M, Siengchin S, Pimenov D Y (2021) Sustainable milling of Ti-6Al-4V: a trade-off between energy efficiency, carbon emissions and machining characteristics under mql and cryogenic environment. Journal of Cleaner Production, 281:125374. https://doi.org/10.1016/j.jclepro.2020.125374 Heisel U, Schaal M, Wolf G (2009) Burr formation in milling with minimum quantity lubrication. Production Engineering, 3(1):23-30. https://doi.org/10.1007/s11740-008-0138-9 Gupta M K, Mia M, Singh G, Pimenov D Y, Sarikaya M, Sharma V S (2019) Hybrid cooling-lubrication strategies to improve surface topography and tool wear in sustainable turning of Al 7075-T6 alloy. The International Journal of Advanced Manufacturing Technology, 101(1-4):55-69. https://doi.org/10.1007/s00170-018-2870-4 Kajaria S, Chittipolu S, Adera S, Hung W N (2012) Micromilling in minimum quantity lubrication. Machining Science and Technology, 16(4):524-546. https://doi.org/10.1080/10910344.2012.730 848 Park K, Suhaimi M A, Yang G, Lee D, Lee S, Kwon P (2017) Milling of titanium alloy with cryogenic cooling and minimum quantity lubrication (mql). International Journal of Precision Engineering and Manufacturing, 18(1):5-14. https://doi.org/10.1007/s12541-017-0001-z Beheshti A, Huang Y, Ohno K, Blakey I, Stokes J R (2020) Improving tribological properties of oil-based lubricants using hybrid colloidal additives. Tribology International, 144:106130. https://doi.org/10.1016/j.triboint.2019.106130 Pereira O, Celaya A, Urbikaín G, Rodríguez A, Fernández-Valdivielso A, Lacalle L N L D (2020) CO 2 cryogenic milling of Inconel 718: cutting forces and tool wear. Journal of Materials Research and Technology, 9(4):8459-8468. https://doi.org/10.1016/j.jmrt.2020.05.118 Yıldırım Ç V (2020) Investigation of hard turning performance of eco-friendly cooling strategies: cryogenic cooling and nanofluid based mql. Tribology International, 144:106127. https://doi.org/10.1016/j.triboint.2019.106127 Iturbe A, Hormaetxe E, Garay A, Arrazola P J (2016) Surface integrity analysis when machining Inconel 718 with conventional and cryogenic cooling. Procedia Cirp, 45:67-70. https://doi.org/10.1016/j.procir.2016.02.095 Shokrani A, Dhokia V, Newman S T (2016) Comparative investigation on using cryogenic machining in CNC milling of Ti-6Al-4V titanium alloy. Machining Science and Technology, 20(3):475-494. https://doi.org/10.1080/10910344.2016.1191953 Yildiz Y, Nalbant M (2008) A review of cryogenic cooling in machining processes. International Journal of Machine Tools and Manufacture, 48(9):947-964. https://doi.org/10.1016 /j.ijmachtools. 2008.01.008 Liu M, Li C, Zhang Y, An Q, Yang M, Gao T, Mao C, Liu B, Cao H, Xu X, Said Z, Debnath S, Jamil M, Ali H M, Sharma S (2021) Cryogenic minimum quantity lubrication machining: from mechanism to application. Frontiers of Mechanical Engineering, 16(4):649-697. https://doi.org/10.1007/s11465-021-0654-2 K N S R, G M, Anwar S, Rahman M A, Erdi Korkmaz M, Gupta M K, Alfaify A, Mia M (2021) Investigation of surface modification and tool wear on milling nimonic 80A under hybrid lubrication. Tribology International, 155 https://doi.org/10.1016/j.triboint.2020.106762 Yıldırım Ç V, Kıvak T, Sarıkaya M, Şirin S (2020) Evaluation of tool wear, surface roughness/topography and chip morphology when machining of Ni-based alloy 625 under mql, cryogenic cooling and cryomql. Journal of Materials Research and Technology, 9(2):2079-2092. https://doi.org/10.1016/j.jmrt.2019.12.069 Tapoglou N, Lopez M I A, Cook I, Taylor C M (2017) Investigation of the influence of CO 2 cryogenic coolant application on tool wear. Procedia Cirp, 63:745-749. https://doi.org/ 10.1016/j.procir.2017.03.351 Khan A M, He N, Li L, Zhao W, Jamil M (2020) Analysis of productivity and machining efficiency in sustainable machining of titanium alloy. Procedia Manufacturing, 43:111-118. https://doi.org/10.1016/j.promfg.2020.02.122 Musfirah A H, Ghani J A, Haron C H C (2017) Tool wear and surface integrity of Inconel 718 in dry and cryogenic coolant at high cutting speed. Wear, 376-377:125-133. https://doi.org /10.1016/j.wear.2017.01.031 Shokrani A, Dhokia V, Newman S T (2012) Environmentally conscious machining of difficult-to-machine materials with regard to cutting fluids. International Journal of Machine Tools & Manufacture, 57:83-101. https://doi.org/10.1016/j.ijmachtools.2012.02.002 Chaabani S, Rodriguez I, Cuesta M, Ayed Y, Arrazola P J, Germain G, Galdos L, Arrazola P, de Argandoña E S, Otegi N, Mendiguren J, Madariaga A, de Buruaga M S (2019) Tool wear and cutting forces when machining Inconel 718 under cryogenic conditions: liquid nitrogen and carbon dioxide. Aip Conference Proceedings, 2113(1) https://doi.org/10.1063/1.5112610 Halim N H A, Haron C H C, Ghani J A, Azhar M F (2019) Tool wear and chip morphology in high-speed milling of hardened Inconel 718 under dry and cryogenic CO 2 conditions. Wear, 426-427:1683-1690. https://doi.org/10.1016/j.wear.2019.01.095 Pereira O, Rodríguez A, Fernández-Abia A I, Barreiro J, López De Lacalle L N (2016) Cryogenic and minimum quantity lubrication for an eco-efficiency turning of AISI 304. Journal of Cleaner Production, 139:440-449. https://doi.org/10.1016/j.jclepro.2016.08.030 Akhtar W, Sun J, Sun P, Chen W, Saleem Z (2014) Tool wear mechanisms in the machining of nickel based super-alloys: a review. Frontiers of Mechanical Engineering, 9(2):106-119. https://doi.org/10.1007/s11465-014-0301-2 Hao Z, Gao D, Fan Y, Han R (2011) New observations on tool wear mechanism in dry machining Inconel718. International Journal of Machine Tools and Manufacture, 51(12):973-979. https://doi.org/10.1016/j.ijmachtools.2011.08.018 Molinari A, Nouari M (2002) Modeling of tool wear by diffusion in metal cutting. Wear, 252(1):135-149. https://doi.org/10.1016/S0043-1648(01)00858-4 Vereschaka A A, Grigoriev S N, Sitnikov N N, Oganyan G V, Batako A (2017) Working efficiency of cutting tools with multilayer nano-structured Ti-TiCN-(Ti,Al)CN and Ti-TiCN-(Ti,Al,Cr)CN coatings: analysis of cutting properties, wear mechanism and diffusion processes. Surface and Coatings Technology, 332:198-213. https://doi.org/10.1016/j.surfcoat. 2017.10.027 Diniz A E, Machado Á R, Corrêa J G (2016) Tool wear mechanisms in the machining of steels and stainless steels. The International Journal of Advanced Manufacturing Technology, 87(9-12):3157-3168. https://doi.org/10.1007/s00170-016-8704-3 Liao Y S, Shiue R H (1996) Carbide tool wear mechanism in turning of Inconel 718 superalloy. Wear, 193(1): 16-24. https://doi.org/10.1016/0043-1648(95)06644-6 Zhang S, Li J F, Deng J X, Li Y S (2009) Investigation on diffusion wear during high-speed machining Ti-6Al-4V alloy with straight tungsten carbide tools. The International Journal of Advanced Manufacturing Technology, 44(1-2):17-25. https://doi.org/10.1007/s00170-008-1803-z Hu X, Shao F, Wang R (2020) Wear mechanism of WC-Co cemented carbide tool in cutting Ti-6Al-4V based on thermodynamics. Journal of Wuhan University of Technology-Mater. Sci. Ed., 35(5):973-979. https://doi.org/10.1007/s11595-020-2344-z Fan Y, Hao Z, Lin J, Yu Z (2015) New observations on tool wear mechanism in machining Inconel 718 under water vapor + air cooling lubrication cutting conditions. Journal of Cleaner Production, 90:381-387. https://doi.org/10.1016/j.jclepro.2014.11.049 Nerz J, Kushner B, Rotolico A (1992) Microstructural evaluation of tungsten carbide-cobalt coatings. Journal of Thermal Spray Technology, 1(2):147-152. https://doi.org/10.1007/ BF02659015 Shi Q, Pan Y, Fu X, Zhou B, Zhang Z (2021) Effect of anisotropy and cutting speed on chip morphology of Ti-6Al-4V under high-speed cutting. The International Journal of Advanced Manufacturing Technology, 113(9-10):2883-2894. https://doi.org/10.1007/s00170-021-06754-8 Xiong Y, Wang W, Jiang R, Lin K, Shao M (2018) Mechanisms and fem simulation of chip formation in orthogonal cutting in-situ TiB2/7050Al MMC. Materials, 11(4):606. https:// doi.org/10.3390/ma11040606 Merchant M E (1945) Mechanics of the metal cutting process. I. Orthogonal cutting and a type 2 chip. Journal of Applied Physics, 16(5):267-275. https://doi.org/10.1063/1.1707586 Ranjan P, Hiremath S S (2021) Investigation of coated tool performance on the machinability, surface residual stress and chip morphology of martensitic aisi 420 steel. Arabian Journal for Science and Engineering, https://doi.org/10.1007/s13369-021-06303-1 Sun S, Brandt M, Dargusch M S (2009) Characteristics of cutting forces and chip formation in machining of titanium alloys. International Journal of Machine Tools and Manufacture, 49(7-8):561-568. https://doi.org/10.1016/j.ijmachtools.2009.02.008 Cite Share Download PDF Status: Published Journal Publication published 28 Feb, 2023 Read the published version in The International Journal of Advanced Manufacturing Technology → Version 1 posted Editorial decision: Major Revisions Needed 30 Oct, 2022 Reviewers agreed at journal 09 Jun, 2022 Reviewers invited by journal 09 Jun, 2022 Editor assigned by journal 09 Jun, 2022 First submitted to journal 07 Jun, 2022 You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. As a division of Research Square Company, we’re committed to making research communication faster, fairer, and more useful. We do this by developing innovative software and high quality services for the global research community. Our growing team is made up of researchers and industry professionals working together to solve the most critical problems facing scientific publishing. Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {"props":{"pageProps":{"initialData":{"identity":"rs-1734237","acceptedTermsAndConditions":true,"allowDirectSubmit":false,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":112371157,"identity":"c73586e7-0678-44c1-b9f6-b21f92ab052a","order_by":0,"name":"Lin Cheng","email":"","orcid":"","institution":"","correspondingAuthor":false,"prefix":"","firstName":"Lin","middleName":"","lastName":"Cheng","suffix":""},{"id":112371158,"identity":"5346f621-1729-4057-acf2-775940e954c2","order_by":1,"name":"Tian Qiu","email":"","orcid":"","institution":"","correspondingAuthor":false,"prefix":"","firstName":"Tian","middleName":"","lastName":"Qiu","suffix":""},{"id":112371159,"identity":"f0c3cef9-32c1-4289-a885-4e19a384058a","order_by":2,"name":"Shizhan Huang","email":"","orcid":"","institution":"","correspondingAuthor":false,"prefix":"","firstName":"Shizhan","middleName":"","lastName":"Huang","suffix":""},{"id":112371160,"identity":"058e073d-e0e3-451c-ba5b-b884d2ad6ead","order_by":3,"name":"Hong Xie","email":"","orcid":"","institution":"","correspondingAuthor":false,"prefix":"","firstName":"Hong","middleName":"","lastName":"Xie","suffix":""},{"id":112371161,"identity":"40eaa74c-fc81-4397-a5fb-8366f20229c6","order_by":4,"name":"Chao Liu","email":"","orcid":"","institution":"","correspondingAuthor":false,"prefix":"","firstName":"Chao","middleName":"","lastName":"Liu","suffix":""},{"id":112371162,"identity":"8da27711-276d-4b08-9601-768a0957b86d","order_by":5,"name":"Yousheng Li","email":"","orcid":"","institution":"","correspondingAuthor":false,"prefix":"","firstName":"Yousheng","middleName":"","lastName":"Li","suffix":""},{"id":112371163,"identity":"5a9b9197-28b0-4e51-9805-225e751e2a2d","order_by":6,"name":"Liangliang Lin","email":"","orcid":"","institution":"","correspondingAuthor":false,"prefix":"","firstName":"Liangliang","middleName":"","lastName":"Lin","suffix":""},{"id":112371164,"identity":"9b9a0df0-6e4e-44f2-be94-284800651d40","order_by":7,"name":"Zhiyang Xiang","email":"","orcid":"","institution":"","correspondingAuthor":false,"prefix":"","firstName":"Zhiyang","middleName":"","lastName":"Xiang","suffix":""},{"id":112371165,"identity":"71a935c4-7538-402e-b180-a5e4fb67159c","order_by":8,"name":"Yan Shui","email":"","orcid":"","institution":"","correspondingAuthor":false,"prefix":"","firstName":"Yan","middleName":"","lastName":"Shui","suffix":""},{"id":112371166,"identity":"2ee29d44-f290-4c35-be17-c391b7babde1","order_by":9,"name":"Fuzeng Wang","email":"","orcid":"","institution":"","correspondingAuthor":false,"prefix":"","firstName":"Fuzeng","middleName":"","lastName":"Wang","suffix":""},{"id":112371167,"identity":"02baf088-cb91-4568-9ff6-358276e36e33","order_by":10,"name":"Xian Wu","email":"","orcid":"","institution":"","correspondingAuthor":false,"prefix":"","firstName":"Xian","middleName":"","lastName":"Wu","suffix":""},{"id":112371168,"identity":"eb47efb6-6f19-46ab-bf21-ba6d28aa5c15","order_by":11,"name":"Lan Yan","email":"","orcid":"","institution":"","correspondingAuthor":false,"prefix":"","firstName":"Lan","middleName":"","lastName":"Yan","suffix":""},{"id":112371169,"identity":"6441856b-e07e-4327-9308-fed33d1c2a2a","order_by":12,"name":"Feng Jiang","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAAA60lEQVRIiWNgGAWjYBACxmYQaQPE7D0QgQbitKQBMc8ZIrVAAEiLRA6RWpjbmZ89/JJgkycf+fbgbR4GG9kNB5ifPcDvMDZzY5mEtGLD23nJ1jwMacYbDrCZG+DXwmAmLfnjcOLG2Tlm0jwMhxM3HOBhk8Cvhf2btETC/8SNM8+AtPwnRguPmeSHhAOJ8yV4QFoOEKWlTJohITlxA0+OseUcg2TjmYfZzPBqMew/vk3yR4Jd4vz2M4Y33lTYyfYdb36GX0sDMKB5gAyDA8CoYQAFFTM+9UAgD3LcDxCjAaRlFIyCUTAKRgEWAACSgkXSpFmUxgAAAABJRU5ErkJggg==","orcid":"https://orcid.org/0000-0003-4938-7798","institution":"Institute of Manufacturing Engineering, Huaqiao University","correspondingAuthor":true,"prefix":"","firstName":"Feng","middleName":"","lastName":"Jiang","suffix":""}],"badges":[],"createdAt":"2022-06-07 12:55:22","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-1734237/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-1734237/v1","draftVersion":[],"editorialEvents":[{"content":"https://doi.org/10.1007/s00170-023-11122-9","type":"published","date":"2023-02-28T19:03:02+00:00"}],"editorialNote":"","failedWorkflow":false,"files":[{"id":22689724,"identity":"ff666a57-e650-403e-aa6b-521bae75d2ca","added_by":"auto","created_at":"2022-06-15 16:38:39","extension":"png","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":73790,"visible":true,"origin":"","legend":"\u003cp\u003eCutting tool geometric parameters and coating\u003c/p\u003e\u003cp\u003e\u003cbr\u003e\u003c/p\u003e","description":"","filename":"1.png","url":"https://assets-eu.researchsquare.com/files/rs-1734237/v1/43aa51248a303e67e6e7d9c8.png"},{"id":22690023,"identity":"c246fefe-b790-4b41-87cf-354d4a0e8d28","added_by":"auto","created_at":"2022-06-15 16:43:39","extension":"png","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":377849,"visible":true,"origin":"","legend":"\u003cp\u003eCutting process\u003c/p\u003e","description":"","filename":"2.png","url":"https://assets-eu.researchsquare.com/files/rs-1734237/v1/788ba62393f88143b9136039.png"},{"id":22689727,"identity":"44e0aceb-82b0-4993-878b-6e0759dd2ef4","added_by":"auto","created_at":"2022-06-15 16:38:39","extension":"png","order_by":3,"title":"Figure 3","display":"","copyAsset":false,"role":"figure","size":304955,"visible":true,"origin":"","legend":"\u003cp\u003eTool wear after dry cutting\u003c/p\u003e","description":"","filename":"3.png","url":"https://assets-eu.researchsquare.com/files/rs-1734237/v1/65fa777492862f4f38f0caee.png"},{"id":22691068,"identity":"44bc689a-4231-40ef-adf1-ba0265a0b9d2","added_by":"auto","created_at":"2022-06-15 16:53:39","extension":"png","order_by":4,"title":"Figure 4","display":"","copyAsset":false,"role":"figure","size":300507,"visible":true,"origin":"","legend":"\u003cp\u003eTool wear after wet cutting\u003c/p\u003e","description":"","filename":"4.png","url":"https://assets-eu.researchsquare.com/files/rs-1734237/v1/4ea5e8d556a1390c3e1d4738.png"},{"id":22689741,"identity":"cbfe5e43-ec27-4469-a8e0-01128b009bc7","added_by":"auto","created_at":"2022-06-15 16:38:40","extension":"png","order_by":5,"title":"Figure 5","display":"","copyAsset":false,"role":"figure","size":318229,"visible":true,"origin":"","legend":"\u003cp\u003eTool wear after cryogenic CO\u003csub\u003e2\u003c/sub\u003e + MQL (oil flow 60 ml/h, temperature -10℃)\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u003c/p\u003e","description":"","filename":"5.png","url":"https://assets-eu.researchsquare.com/files/rs-1734237/v1/f31a96de289186486324eb90.png"},{"id":22689732,"identity":"607454c3-bd22-40be-9a2a-eb201f6f12fb","added_by":"auto","created_at":"2022-06-15 16:38:39","extension":"png","order_by":6,"title":"Figure 6","display":"","copyAsset":false,"role":"figure","size":298480,"visible":true,"origin":"","legend":"\u003cp\u003eTool wear after cryogenic CO\u003csub\u003e2\u003c/sub\u003e+ MQL\t(oil flow 60 ml/h, temperature -30℃)\u003c/p\u003e\u003cp\u003e\u003cbr\u003e\u003c/p\u003e","description":"","filename":"6.png","url":"https://assets-eu.researchsquare.com/files/rs-1734237/v1/8a509245a891efbf8eb800c4.png"},{"id":22690425,"identity":"f6b1d14d-66ee-46c4-8f6d-e08cb29a15af","added_by":"auto","created_at":"2022-06-15 16:48:40","extension":"png","order_by":7,"title":"Figure 7","display":"","copyAsset":false,"role":"figure","size":299209,"visible":true,"origin":"","legend":"\u003cp\u003eTool wear after cryogenic CO\u003csub\u003e2\u003c/sub\u003e + MQL\u003cstrong\u003e\u0026nbsp;\u003c/strong\u003e(oil flow 60 ml/h, temperature -50℃)\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u003c/p\u003e","description":"","filename":"7.png","url":"https://assets-eu.researchsquare.com/files/rs-1734237/v1/9a82b079425bab98140cc9f2.png"},{"id":22754712,"identity":"36a07fbf-2029-45aa-8d8c-e52ae804e767","added_by":"auto","created_at":"2022-06-17 03:49:00","extension":"png","order_by":8,"title":"Figure 8","display":"","copyAsset":false,"role":"figure","size":333529,"visible":true,"origin":"","legend":"\u003cp\u003eTool wear after cryogenic CO\u003csub\u003e2\u003c/sub\u003e + MQL(oil flow 0 ml/h, temperature -50℃)\u0026nbsp;\u0026nbsp;\u003c/p\u003e","description":"","filename":"8.png","url":"https://assets-eu.researchsquare.com/files/rs-1734237/v1/263d82d363faf35eb1e59e24.png"},{"id":22690025,"identity":"5e9be6ce-23fe-4c1d-af43-0a98e9b9444f","added_by":"auto","created_at":"2022-06-15 16:43:39","extension":"png","order_by":9,"title":"Figure 9","display":"","copyAsset":false,"role":"figure","size":298029,"visible":true,"origin":"","legend":"\u003cp\u003eTool wear after cryogenic CO\u003csub\u003e2\u003c/sub\u003e + MQL\u003cstrong\u003e\u0026nbsp;\u003c/strong\u003e(oil flow 40 ml/h, temperature -50℃)\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u003c/p\u003e","description":"","filename":"9.png","url":"https://assets-eu.researchsquare.com/files/rs-1734237/v1/515d65802f69a3ea718df6af.png"},{"id":22690424,"identity":"7522b1ab-a46f-4560-9874-f3970229585b","added_by":"auto","created_at":"2022-06-15 16:48:39","extension":"png","order_by":10,"title":"Figure 10","display":"","copyAsset":false,"role":"figure","size":303202,"visible":true,"origin":"","legend":"\u003cp\u003eTool wear after cryogenic CO\u003csub\u003e2\u003c/sub\u003e + MQL(oil flow 80 ml/h, temperature -50℃)\u0026nbsp;\u0026nbsp;\u003c/p\u003e","description":"","filename":"10.png","url":"https://assets-eu.researchsquare.com/files/rs-1734237/v1/bc1cc1f3b228baf6e6749580.png"},{"id":22689744,"identity":"eb5d32fc-f906-45c1-9589-7482367af7c6","added_by":"auto","created_at":"2022-06-15 16:38:40","extension":"png","order_by":11,"title":"Figure 11","display":"","copyAsset":false,"role":"figure","size":389166,"visible":true,"origin":"","legend":"\u003cp\u003eAdhesive tool wear after dry cutting\u003c/p\u003e","description":"","filename":"11.png","url":"https://assets-eu.researchsquare.com/files/rs-1734237/v1/12746520388832443e7fab08.png"},{"id":22691453,"identity":"dca7e930-5bb1-4285-9940-9727d6be1ef6","added_by":"auto","created_at":"2022-06-15 16:58:40","extension":"png","order_by":12,"title":"Figure 12","display":"","copyAsset":false,"role":"figure","size":373214,"visible":true,"origin":"","legend":"\u003cp\u003eAdhesive tool wear after wet cutting\u0026nbsp;\u003c/p\u003e","description":"","filename":"12.png","url":"https://assets-eu.researchsquare.com/files/rs-1734237/v1/c6af7474f2f89053c1b03e2e.png"},{"id":22691076,"identity":"57b91810-cf02-41eb-8b35-451db31c9353","added_by":"auto","created_at":"2022-06-15 16:53:40","extension":"png","order_by":13,"title":"Figure 13","display":"","copyAsset":false,"role":"figure","size":391527,"visible":true,"origin":"","legend":"\u003cp\u003eAdhesive tool wear after Cryogenic CO\u003csub\u003e2\u003c/sub\u003e-assisted\u003c/p\u003e\u003cp\u003eMQL (oil flow 60ml/h, temperature -50℃)\u003c/p\u003e\u003cp\u003e\u003cbr\u003e\u003c/p\u003e","description":"","filename":"13.png","url":"https://assets-eu.researchsquare.com/files/rs-1734237/v1/79f14f2e394b194b8cda3156.png"},{"id":22691070,"identity":"e4dfbe5d-3a5c-4313-96d6-00ec1e6443ce","added_by":"auto","created_at":"2022-06-15 16:53:39","extension":"png","order_by":14,"title":"Figure 14","display":"","copyAsset":false,"role":"figure","size":216418,"visible":true,"origin":"","legend":"\u003cp\u003eEnergy spectrum analysis area and analysis diagram\u003c/p\u003e","description":"","filename":"14.png","url":"https://assets-eu.researchsquare.com/files/rs-1734237/v1/58c7e48bd497f55597d0cbd8.png"},{"id":22690421,"identity":"1c4f0f2a-0ebe-4288-a41d-8345b60b08f8","added_by":"auto","created_at":"2022-06-15 16:48:39","extension":"png","order_by":15,"title":"Figure 15","display":"","copyAsset":false,"role":"figure","size":67961,"visible":true,"origin":"","legend":"\u003cp\u003eMass percentage of Fe and Cr elements\u003c/p\u003e","description":"","filename":"15.png","url":"https://assets-eu.researchsquare.com/files/rs-1734237/v1/a4f5acbbfff17e9a9b43ee7b.png"},{"id":22690036,"identity":"fcb52533-af0e-4be6-b50f-4582449bcefd","added_by":"auto","created_at":"2022-06-15 16:43:40","extension":"png","order_by":16,"title":"Figure 16","display":"","copyAsset":false,"role":"figure","size":243316,"visible":true,"origin":"","legend":"\u003cp\u003e\tDistribution of Fe and Cr elements\u003c/p\u003e","description":"","filename":"16.png","url":"https://assets-eu.researchsquare.com/files/rs-1734237/v1/b43bce2301575651388bd581.png"},{"id":22691458,"identity":"98e99ecb-c65c-4911-a415-d4162bbe746e","added_by":"auto","created_at":"2022-06-15 16:58:40","extension":"png","order_by":17,"title":"Figure 17","display":"","copyAsset":false,"role":"figure","size":102489,"visible":true,"origin":"","legend":"\u003cp\u003eMass percentage of O element\u003c/p\u003e\u003cp\u003e\u003cbr\u003e\u003c/p\u003e","description":"","filename":"17.png","url":"https://assets-eu.researchsquare.com/files/rs-1734237/v1/843c1ea81153d5f19f9e8d6e.png"},{"id":22689733,"identity":"6b1a16d7-25e3-4e5f-8b3f-8fbb5a5ed29e","added_by":"auto","created_at":"2022-06-15 16:38:39","extension":"png","order_by":18,"title":"Figure 18","display":"","copyAsset":false,"role":"figure","size":123435,"visible":true,"origin":"","legend":"\u003cp\u003eDistribution of O element\u003c/p\u003e","description":"","filename":"18.png","url":"https://assets-eu.researchsquare.com/files/rs-1734237/v1/b60ed11118113b6b6648ca47.png"},{"id":22690429,"identity":"cc20f444-eddc-40ab-94fe-504aea7ca613","added_by":"auto","created_at":"2022-06-15 16:48:40","extension":"png","order_by":19,"title":"Figure 19","display":"","copyAsset":false,"role":"figure","size":145366,"visible":true,"origin":"","legend":"\u003cp\u003eChip sampling position\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;(the left side in the Fig. is the chip tail )\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u003c/p\u003e","description":"","filename":"19.png","url":"https://assets-eu.researchsquare.com/files/rs-1734237/v1/e8815f2d0b1a380a284a999a.png"},{"id":22690039,"identity":"bc5c7c95-a940-4c70-bc53-5f28cda6b875","added_by":"auto","created_at":"2022-06-15 16:43:40","extension":"png","order_by":20,"title":"Figure 20","display":"","copyAsset":false,"role":"figure","size":83991,"visible":true,"origin":"","legend":"\u003cp\u003eGeometric parameters of the\u0026nbsp;\tsawtooth chip\u003c/p\u003e","description":"","filename":"20.png","url":"https://assets-eu.researchsquare.com/files/rs-1734237/v1/3b07a327f58b2f132320518b.png"},{"id":22689737,"identity":"1743d7b1-3bce-4deb-92a9-35e633451f32","added_by":"auto","created_at":"2022-06-15 16:38:40","extension":"png","order_by":21,"title":"Figure 21","display":"","copyAsset":false,"role":"figure","size":476088,"visible":true,"origin":"","legend":"\u003cp\u003eMicro-morphology of dry cutting, wet cutting, and the optimal parameter array at 5mm\u003c/p\u003e","description":"","filename":"21.png","url":"https://assets-eu.researchsquare.com/files/rs-1734237/v1/82e1be45705a0b83360d0eb5.png"},{"id":22690033,"identity":"51ae427b-7f33-40e4-a592-92cf9ee49d8e","added_by":"auto","created_at":"2022-06-15 16:43:40","extension":"png","order_by":22,"title":"Figure 22","display":"","copyAsset":false,"role":"figure","size":550442,"visible":true,"origin":"","legend":"\u003cp\u003eMicro-morphology of dry cutting, wet cutting, and the optimal parameter array at 10mm\u003c/p\u003e\u003cp\u003e\u003cbr\u003e\u003c/p\u003e","description":"","filename":"22.png","url":"https://assets-eu.researchsquare.com/files/rs-1734237/v1/bff707fb028562b4d7a14132.png"},{"id":22690431,"identity":"fe073f4c-ff0d-447d-93ba-ca50d47bd242","added_by":"auto","created_at":"2022-06-15 16:48:40","extension":"png","order_by":23,"title":"Figure 23","display":"","copyAsset":false,"role":"figure","size":196225,"visible":true,"origin":"","legend":"\u003cp\u003eSerrated degree and frequency of dry cutting, wet cutting, and the optimal parameter array\u003c/p\u003e","description":"","filename":"23.png","url":"https://assets-eu.researchsquare.com/files/rs-1734237/v1/b9480d0653953b4c7d80a280.png"},{"id":22690029,"identity":"d42dbdbc-6ced-4fdd-b9eb-55c4d968b246","added_by":"auto","created_at":"2022-06-15 16:43:39","extension":"png","order_by":24,"title":"Figure 24","display":"","copyAsset":false,"role":"figure","size":84656,"visible":true,"origin":"","legend":"\u003cp\u003eThe width of the second deformation zone(ε\u003csub\u003eπ\u003c/sub\u003e) of dry cutting, wet cutting, and the optimal parameter array\u003c/p\u003e","description":"","filename":"24.png","url":"https://assets-eu.researchsquare.com/files/rs-1734237/v1/19e30bf7e1af2f7d9e8d70b8.png"},{"id":22689749,"identity":"168ef518-1b79-46eb-91a5-ec4a8744a941","added_by":"auto","created_at":"2022-06-15 16:38:40","extension":"png","order_by":25,"title":"Figure 25","display":"","copyAsset":false,"role":"figure","size":321548,"visible":true,"origin":"","legend":"\u003cp\u003eSchematic diagram of sampling points for non-free surface microhardness analysis of dry cutting, wet cutting, and the optimal parameter array\u003c/p\u003e","description":"","filename":"25.png","url":"https://assets-eu.researchsquare.com/files/rs-1734237/v1/a2df0d86dc9dde344608d4c8.png"},{"id":22689747,"identity":"c0c0f325-aa3b-48f5-9010-b4f7c5ba8c42","added_by":"auto","created_at":"2022-06-15 16:38:40","extension":"png","order_by":26,"title":"Figure 26","display":"","copyAsset":false,"role":"figure","size":122165,"visible":true,"origin":"","legend":"\u003cp\u003eNon-free surface vickers hardness of dry cutting, wet cutting\u003c/p\u003e\u003cp\u003eand the optimal parameter array\u003c/p\u003e\u003cp\u003e\u003cbr\u003e\u003c/p\u003e","description":"","filename":"26.png","url":"https://assets-eu.researchsquare.com/files/rs-1734237/v1/8a4fb3d1dffb064f7e83ce5a.png"},{"id":44720372,"identity":"f01f7b98-7f6a-4f79-8a17-f16bea8489fb","added_by":"auto","created_at":"2023-10-16 19:11:12","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":6993878,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-1734237/v1/8125d3d6-6f73-41a1-9750-8668779bec35.pdf"}],"financialInterests":"","formattedTitle":"Study on Tool wear mechanism under Cryogenic CO2-Assisted Minimum Quantity Lubrication Technology","fulltext":[{"header":"1 Introduction","content":"\u003cp\u003eThe use of cutting fluids is widely in machining. However, conventional cutting fluids cooling has high consumption and production costs[\u003cspan additionalcitationids=\"CR2\" citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e], causes serious environmental pollution, and harms the health of operators[\u003cspan additionalcitationids=\"CR5\" citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e]. Green cutting technology is developed to solve these problems. At present, green cutting technology mainly includes dry cutting, minimum quantity lubrication (MQL), cryogenic cutting, cryogenic minimum quantity lubrication, and so on[\u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e, \u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e]. In the machining of difficult-to-machine materials, dry cutting has the lowest cost, but it has high cutting temperature and cutting force[\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e, \u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e]. MQL can be applied to the machining of aluminum alloy, stainless steel, and carbon structural steel[\u003cspan additionalcitationids=\"CR12\" citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e]. However, it is prone to insufficient cooling, and the cooling effect is poor when the cutting temperature is high[\u003cspan additionalcitationids=\"CR15\" citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR16\" class=\"CitationRef\"\u003e16\u003c/span\u003e]. Cryogenic cutting technology includes cryogenic CO\u003csub\u003e2\u003c/sub\u003e cooling, cryogenic nitrogen cooling, cryogenic air cooling, etc. Quite a few examine have researched that cryogenic cutting technology is mainly used in the processing of titanium alloy, magnesium alloy, superalloy, and high-strength steel[\u003cspan additionalcitationids=\"CR18\" citationid=\"CR17\" class=\"CitationRef\"\u003e17\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR19\" class=\"CitationRef\"\u003e19\u003c/span\u003e], which can improve the tool life and processing quality[\u003cspan citationid=\"CR20\" class=\"CitationRef\"\u003e20\u003c/span\u003e]. However, the lubrication effect of cryogenic cutting is unfavorable[\u003cspan citationid=\"CR21\" class=\"CitationRef\"\u003e21\u003c/span\u003e, \u003cspan citationid=\"CR22\" class=\"CitationRef\"\u003e22\u003c/span\u003e]. Previous studies of the machining of difficult-to-machine materials have presented that minimum quantity lubrication technology at low temperature has significant advantages in improving the processing quality and tool life[\u003cspan additionalcitationids=\"CR24\" citationid=\"CR23\" class=\"CitationRef\"\u003e23\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR25\" class=\"CitationRef\"\u003e25\u003c/span\u003e]. Cryogenic minimum quantity lubrication technology is a method combining cryogenic cutting and minimum quantity lubrication, which includes cryogenic air-assisted MQL, cryogenic nitrogen-assisted MQL, cryogenic CO\u003csub\u003e2\u003c/sub\u003e-assisted MQL, and so on. In the machining of difficult-to-machine materials, although the cryogenic air-assisted MQL can reduce the tool wear and improve the tool life, the cooling effect is limited[\u003cspan citationid=\"CR21\" class=\"CitationRef\"\u003e21\u003c/span\u003e]. Cryogenic nitrogen-assisted MQL can reduce the cutting force and improve processing quality, but the effect of reducing tool wear is less impressive[\u003cspan citationid=\"CR26\" class=\"CitationRef\"\u003e26\u003c/span\u003e, \u003cspan citationid=\"CR27\" class=\"CitationRef\"\u003e27\u003c/span\u003e]. However, previous studies of the cryogenic CO\u003csub\u003e2\u003c/sub\u003e-assisted MQL have emphasized favorable advantages in reducing tool wear and improving tool life[\u003cspan additionalcitationids=\"CR29\" citationid=\"CR28\" class=\"CitationRef\"\u003e28\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR30\" class=\"CitationRef\"\u003e30\u003c/span\u003e]. In addition, cryogenic CO\u003csub\u003e2\u003c/sub\u003e-assisted MQL has the advantages of low cost, non-toxic, and non-pollution, and has widespread use in practical production. The use of cryogenic CO\u003csub\u003e2\u003c/sub\u003e is beneficial to the realization of carbon neutralization and peak target to a certain extent[\u003cspan citationid=\"CR30\" class=\"CitationRef\"\u003e30\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eHowever, cryogenic CO\u003csub\u003e2\u003c/sub\u003e-assisted MQL is a green cutting technology that is more likely to replace cutting fluid, and there are a few pieces of research in the field. In this study, the effect of cryogenic CO\u003csub\u003e2\u003c/sub\u003e temperature and minimum quantity lubrication oil flow in milling experiments of difficult-to-machine materials was examined. In regards to this study, the tool wear form, wear mechanism, and chip morphology in the cryogenic CO\u003csub\u003e2\u003c/sub\u003e-assisted MQL were studied, compared with those in the wet and dry cutting. This work provided a theoretical basis for the application of cryogenic CO\u003csub\u003e2\u003c/sub\u003e-assisted MQL in the processing of difficult-to-machine materials.\u003c/p\u003e"},{"header":"2 Materials And Methods","content":"\u003cp\u003eIn this study, N87 alloy steel was used as the workpiece, which is a typical difficult-to-machine material. The main chemical composition of\u0026nbsp;N87 alloy steel was presented in Table 1, and the\u0026nbsp;mechanical and physical properties of N87 was shown in\u0026nbsp;Table 2.\u0026nbsp;The APKT1604PDTR KC725M cemented carbide tool and mircolube cryo 75 minimum quantity lubrication oil were selected for the milling experiments, cutting tool geometric parameters and coating structure were shown in Fig. 1. All the milling experiments were carried out in the VMC-1600 CNC of Shenyang, and the cutting parameter was shown in Table 3.\u003c/p\u003e\n\u003cp style=\"text-align: center;\"\u003e\u003cstrong\u003eTable 1\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n\u003cp style=\"text-align: center;\"\u003eChemical composition of N87 (wt%)\u003c/p\u003e\n\u003cdiv align=\"center\"\u003e\n \u003ctable border=\"1\" cellpadding=\"0\" cellspacing=\"0\" width=\"0\"\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd width=\"10.327868852459016%\"\u003e\n \u003cp\u003eElement\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"6.229508196721311%\"\u003e\n \u003cp\u003eC\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"6.229508196721311%\"\u003e\n \u003cp\u003eSi\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"7.868852459016393%\"\u003e\n \u003cp\u003eMn\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"9.01639344262295%\"\u003e\n \u003cp\u003eCr\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"7.868852459016393%\"\u003e\n \u003cp\u003eNi\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"5.245901639344262%\"\u003e\n \u003cp\u003eCo\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"7.868852459016393%\"\u003e\n \u003cp\u003eW\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"7.868852459016393%\"\u003e\n \u003cp\u003eMo\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"7.868852459016393%\"\u003e\n \u003cp\u003eV\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"7.868852459016393%\"\u003e\n \u003cp\u003eNb\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"7.213114754098361%\"\u003e\n \u003cp\u003eN\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"8.524590163934427%\"\u003e\n \u003cp\u003eFe\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"10.327868852459016%\"\u003e\n \u003cp\u003eMass fraction\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"6.229508196721311%\"\u003e\n \u003cp\u003e0.08\u003c/p\u003e\n \u003cp\u003e～\u003c/p\u003e\n \u003cp\u003e0.13\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"6.229508196721311%\"\u003e\n \u003cp\u003e\u0026le;0.1\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"7.868852459016393%\"\u003e\n \u003cp\u003e0.35～\u003c/p\u003e\n \u003cp\u003e0.65\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"9.01639344262295%\"\u003e\n \u003cp\u003e10.00～\u003c/p\u003e\n \u003cp\u003e12.00\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"7.868852459016393%\"\u003e\n \u003cp\u003e0.30～\u003c/p\u003e\n \u003cp\u003e0.70\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"5.245901639344262%\"\u003e\n \u003cp\u003e2.5\u003c/p\u003e\n \u003cp\u003e～\u003c/p\u003e\n \u003cp\u003e3.5\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"7.868852459016393%\"\u003e\n \u003cp\u003e2.40～\u003c/p\u003e\n \u003cp\u003e3.00\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"7.868852459016393%\"\u003e\n \u003cp\u003e0.10～\u003c/p\u003e\n \u003cp\u003e0.40\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"7.868852459016393%\"\u003e\n \u003cp\u003e0.15～\u003c/p\u003e\n \u003cp\u003e0.25\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"7.868852459016393%\"\u003e\n \u003cp\u003e0.05～\u003c/p\u003e\n \u003cp\u003e0.12\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"7.213114754098361%\"\u003e\n \u003cp\u003e0.01\u003c/p\u003e\n \u003cp\u003e～\u003c/p\u003e\n \u003cp\u003e0.035\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"8.524590163934427%\"\u003e\n \u003cp\u003eOthers\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n \u003c/table\u003e\n\u003c/div\u003e\n\u003cp\u003e\u003cbr\u003e\u003c/p\u003e\n\u003cp style=\"text-align: center;\"\u003e\u003cstrong\u003eTable 2\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n\u003cp style=\"text-align: center;\"\u003eMechanical and physical properties of N87\u003c/p\u003e\n\u003cdiv align=\"center\"\u003e\n \u003ctable border=\"1\" cellpadding=\"0\" cellspacing=\"0\" width=\"0\"\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd width=\"20.68345323741007%\"\u003e\n \u003cp\u003eYield strength (MPa)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"20.68345323741007%\"\u003e\n \u003cp\u003eUltimate tensile strength (MPa)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"23.56115107913669%\"\u003e\n \u003cp\u003eElongation\u003c/p\u003e\n \u003cp\u003e(%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"19.964028776978417%\"\u003e\n \u003cp\u003eShrinkage\u003c/p\u003e\n \u003cp\u003e(%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"15.107913669064748%\"\u003e\n \u003cp\u003eHardness (HB)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"20.68345323741007%\"\u003e\n \u003cp\u003e620\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"20.68345323741007%\"\u003e\n \u003cp\u003e885\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"23.56115107913669%\"\u003e\n \u003cp\u003e15\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"19.964028776978417%\"\u003e\n \u003cp\u003e45\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"15.107913669064748%\"\u003e\n \u003cp\u003e321\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n \u003c/table\u003e\n\u003c/div\u003e\n\u003cp\u003e\u0026nbsp;\u003c/p\u003e\n\u003cp style=\"text-align: center;\"\u003e\u003cstrong\u003eTable 3\u003c/strong\u003e\u003c/p\u003e\n\u003cp style=\"text-align: center;\"\u003e\u003cstrong\u003e\u0026nbsp;\u003c/strong\u003eCutting parameter\u003c/p\u003e\n\u003ctable border=\"1\" cellpadding=\"0\" cellspacing=\"0\" style=\"border-collapse: collapse; margin: 0px auto;\"\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" width=\"15.398550724637682%\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd colspan=\"2\" valign=\"top\" width=\"17.934782608695652%\"\u003e\n \u003cp\u003eCutting speed (m/min)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"16.666666666666668%\"\u003e\n \u003cp\u003eFeed rate (mm/rev)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"16.666666666666668%\"\u003e\n \u003cp\u003eCutting depth (mm)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"16.666666666666668%\"\u003e\n \u003cp\u003eCutting width (mm)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"16.666666666666668%\"\u003e\n \u003cp\u003eCutting length (m)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd colspan=\"2\" width=\"16.666666666666668%\"\u003e\n \u003cp\u003eCutting parameter\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"16.666666666666668%\"\u003e\n \u003cp\u003e158\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"16.666666666666668%\"\u003e\n \u003cp\u003e0.12\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"16.666666666666668%\"\u003e\n \u003cp\u003e1\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"16.666666666666668%\"\u003e\n \u003cp\u003e21\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"16.666666666666668%\"\u003e\n \u003cp\u003e10.5\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"15.398550724637682%\"\u003e\u003cbr\u003e\u003c/td\u003e\n \u003ctd width=\"1.2681159420289856%\"\u003e\u003cbr\u003e\u003c/td\u003e\n \u003ctd width=\"16.666666666666668%\"\u003e\u003cbr\u003e\u003c/td\u003e\n \u003ctd width=\"16.666666666666668%\"\u003e\u003cbr\u003e\u003c/td\u003e\n \u003ctd width=\"16.666666666666668%\"\u003e\u003cbr\u003e\u003c/td\u003e\n \u003ctd width=\"16.666666666666668%\"\u003e\u003cbr\u003e\u003c/td\u003e\n \u003ctd width=\"16.666666666666668%\"\u003e\u003cbr\u003e\u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n\u003c/table\u003e\n\u003cp\u003eAs shown in Table 4, different CO\u003csub\u003e2\u003c/sub\u003e temperatures and minimum quantity lubrication oil flow were designed in the milling experiments. In addition, the experiments of dry cutting and wet cutting were carried out, which have been seen as comparative milling experiments. The cutting process was shown in Fig. 2. The wear of the collected tools under different cooling conditions was observed and compared. In this work, Kroll reagent and alcohol ultrasonic cleaning methods were used to remove the adhesive chips and other impurities on the tool. The tool wear and chips were observed by scanning electron microscope (SEM), and the elemental analysis of the tool surface was analyzed by energy dispersive spectrometer(EDS).\u003c/p\u003e\n\u003cp style=\"text-align: center;\"\u003e\u003cstrong\u003eTable 4\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n\u003cp style=\"text-align: center;\"\u003eDesign of experiments\u003c/p\u003e\n\u003cdiv align=\"center\"\u003e\n \u003ctable border=\"0\" cellpadding=\"0\" cellspacing=\"0\"\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd valign=\"bottom\" width=\"46.68008048289738%\"\u003e\n \u003cp style=\"text-align: right;\"\u003eExperimental parameters\u003c/p\u003e\n \u003cp\u003eLubrication methods\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"17.706237424547282%\"\u003e\n \u003cp\u003eOil flow (ml/h)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"17.907444668008047%\"\u003e\n \u003cp\u003eTemperature (℃)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"17.706237424547282%\"\u003e\n \u003cp\u003eGroup\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"46.68008048289738%\"\u003e\n \u003cp\u003eDry cutting\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"17.706237424547282%\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"17.907444668008047%\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"17.706237424547282%\"\u003e\n \u003cp\u003e1\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"46.68008048289738%\"\u003e\n \u003cp\u003eWet cutting\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"17.706237424547282%\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"17.907444668008047%\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"17.706237424547282%\"\u003e\n \u003cp\u003e2\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd rowspan=\"6\" width=\"46.68008048289738%\"\u003e\n \u003cp\u003eCryogenic CO\u003csub\u003e2\u003c/sub\u003e-assisted MQL\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"17.706237424547282%\"\u003e\n \u003cp\u003e60\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"17.907444668008047%\"\u003e\n \u003cp\u003e-10\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"17.706237424547282%\"\u003e\n \u003cp\u003e3\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" width=\"33.20754716981132%\"\u003e\n \u003cp\u003e60\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"33.58490566037736%\"\u003e\n \u003cp\u003e-30\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"33.20754716981132%\"\u003e\n \u003cp\u003e4\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" width=\"33.20754716981132%\"\u003e\n \u003cp\u003e60\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"33.58490566037736%\"\u003e\n \u003cp\u003e-50\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"33.20754716981132%\"\u003e\n \u003cp\u003e5\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" width=\"33.20754716981132%\"\u003e\n \u003cp\u003e0\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"33.58490566037736%\"\u003e\n \u003cp\u003e-50\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"33.20754716981132%\"\u003e\n \u003cp\u003e6\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" width=\"33.20754716981132%\"\u003e\n \u003cp\u003e40\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"33.58490566037736%\"\u003e\n \u003cp\u003e-50\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"33.20754716981132%\"\u003e\n \u003cp\u003e7\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" width=\"33.20754716981132%\"\u003e\n \u003cp\u003e80\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"33.58490566037736%\"\u003e\n \u003cp\u003e-50\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"33.20754716981132%\"\u003e\n \u003cp\u003e8\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n \u003c/table\u003e\n\u003c/div\u003e"},{"header":"3 Results","content":"\u003cp\u003e\u003cstrong\u003e3.1 Tool wear form\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eIn Fig. 3, the wear form of the rake face under dry cutting was shown, and the overall wear was serious. Due to the high cutting temperature and poor lubrication conditions, the coating of the main cutting edge was peeled off seriously, and micro-chipping occured in the fillet area of the tool tip. As seen in Fig. 4, the wear form of rake face under wet cutting cooling was normal wear of cutting edge and peeling of the coating.\u0026nbsp;This benefited from the low temperature and\u0026nbsp;favorable lubrication of the cutting area.\u003c/p\u003e\n\u003cp\u003eFigures\u0026nbsp;5-7 showed the wear form of rake face under cryogenic CO\u003csub\u003e2\u003c/sub\u003e-assisted MQL experiments when oil flow was kept unchanged at 60 ml/h and cryogenic CO\u003csub\u003e2\u0026nbsp;\u003c/sub\u003etemperature\u0026nbsp;was set to -10℃, -30℃ and -50℃. As shown in Fig. 5, the main cutting edge of the tool under -10 ℃ had a large area of chipping, and the coating of the\u0026nbsp;minor cutting edge peeled off seriously.\u0026nbsp;Figure 6 clearly showed that the micro-chipping and crater wear appeared on the main cutting edge of the tool under -30℃, and the serious coating material damage appeared in the fillet area of the tool tip. In addition, when the CO\u003csub\u003e2\u003c/sub\u003e temperature was -50℃, the main cutting edge of the tool was in good condition and the coating was worn evenly, as shown in Fig. 7. It can be found that the tool wear decreases gradually with the decrease of cryogenic CO\u003csub\u003e2\u003c/sub\u003e temperature when comparing the tool wear forms of three experimental groups. When the cryogenic CO\u003csub\u003e2\u003c/sub\u003e temperature was -50℃, the tool wear was lighter than that of -10℃ and -30℃. The reason is that after the temperature is reduced, the cryogenic CO\u003csub\u003e2\u003c/sub\u003e carrier can make the oil mist reach the cutting area stably, which can make the lubrication conditions well. In addition, when the cryogenic CO\u003csub\u003e2\u003c/sub\u003e temperature was -50℃, the cooling effect was favorable. The wear form of the rake face under -10℃ and -30℃ was more serious than that during dry cutting, because the lubricating oil cannot get into the cutting area steadily which results in instability of the cutting state and serious tool wear, and the cooling effect was unfavorable.\u003c/p\u003e\n\u003cp\u003eFigures\u0026nbsp;7-10 showed the wear form of rake faces under cryogenic CO\u003csub\u003e2\u003c/sub\u003e-assisted MQL experiments when cryogenic CO\u003csub\u003e2\u003c/sub\u003e temperature was kept unchanged at -50℃ and oil flow was set to \u0026nbsp;0 ml/h, 40 ml/h, 60 ml/h and 80 ml/h. As seen in Fig. 8, the crater wear and coating peeling appeared on the main cutting edge of the tool when the oil flow was 0 ml/h. In addition, the local coating peeling occurred on the minor cutting edge. As illustrated in Fig. 9, although the tool crater wear was reduced, the coating peeling was still uneven and also occurred on the minor cutting edge. However, when the oil flow is 60 ml/h, the main cutting edge was worn evenly without abnormal wear, as shown in Fig. 7. In Fig. 8, the wear form of the rake face when oil flow was 80 ml/h was shown. Although the wear of the main cutting edge was uniform, the coating peeling was more serious than that when oil flow was 60 ml/h and the small range of coating peeling occurred on the minor cutting edge. Compared with the tool wear forms of the four experiment groups, the tool wear was generally reduced with the increase of minimum quantity lubrication oil flow. The main reason for the improvement of tool wear was that the lubrication conditions in the cutting area become better with the increase in oil flow. Thus, the friction between the tool and workpiece or chip was reduced, and the tool wear was improved. However, when the lubricating oil flow was too large, the particles of oil mist will increase, making it more difficult for oil mist to enter the cutting area. Consequently, the lubrication effect decreased and the tool wear increased.\u003c/p\u003e\n\u003cp\u003eBased on the above analysis,\u0026nbsp;it\u0026nbsp;indicates\u0026nbsp;that the experimental group which oil flow is 60 ml/h and the cryogenic CO\u003csub\u003e2\u003c/sub\u003e temperature is -50℃ has the lightest tool wear and the experimental parameters are optimal.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e3.2 Tool wear mechanism\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e3.2.1 Adhesive wear\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eFigures\u0026nbsp;11-13 showed the\u0026nbsp;comparison diagram of the rake face before and after tool etching in the experiments of dry cutting, wet cutting, and the optimal parameter array of cryogenic CO\u003csub\u003e2\u003c/sub\u003e-assisted MQL. Through the comparison, the chip adhesion and adhesive wear area can be clearly seen. In the cutting process, the high cutting temperature and high pressure will be produced in the tool-chip contact area zone, resulting in cold welding, which makes the workpiece material easy to bond to the cutting edge of the tool[31,32]. The adhesion workpiece material fell off under intermittent mechanical impact load during the high-speed milling, and the coating material will be taken away, which results in adhesive wear on the tool surface. With the progress of cutting, the bonding and peeling process of workpiece materials were repeated, resulting in the aggravation of adhesive wear.\u003c/p\u003e\n\u003cp\u003eAs shown in Fig. 11,\u0026nbsp;the adhesive wear of the tool during dry cutting was serious on the main cutting edge and the fillet area of the tool tip, and also occurred on the minor cutting edge. In addition, the damage caused by bonding and tearing on the fillet area of the tool tip was also shown in Fig. 11. This was mainly due to the poor cooling and lubrication condition, which leads to the high\u0026nbsp;temperature under alternating mechanical stress and thermal stress. In this case, the bonding of workpiece material was more serious under high temperature and pressure, and the adhesion layer was easier to fall off during processing due to the high friction in the tool-chip contact area, resulting in serious adhesive wear. As seen in Fig.\u0026nbsp;12,\u0026nbsp;the adhesive wear of the tool was relatively light under wet cutting cooling and the chip adhesive area was small and mainly occurred on the main cutting edge. This benefitted from the favorable cooling and lubrication condition, and the low\u0026nbsp;temperature and friction in the tool-chip contact area zone.\u003c/p\u003e\n\u003cp\u003eFigure\u0026nbsp;13 showed the\u0026nbsp;tool adhesive wear of the optimal parameter array (oil flow 60 ml/h, CO\u003csub\u003e2\u003c/sub\u003e temperature -50℃), it can be found that the chip adhesive area was small and mainly occurred on the main cutting edge. The area and degree of adhesive wear was better than that of dry cutting tool, and more uniform than that of wet cutting tool. The reason was that the extremely low temperature and the phase transformation of liquid CO\u003csub\u003e2\u003c/sub\u003e when it reached the tool-chip contact area zone can effectively reduce the cutting temperature, maintain the hardness of tool surface, and reduce the impact of the adhesive layer falling off on the tool coating. In addition, under the protection of cryogenic CO\u003csub\u003e2\u0026nbsp;\u003c/sub\u003eat temperature -50℃, the lubricating oil mist can stably and effectively enter the tool-chip contact area zone, which can reduce the cutting force and the adhesive wear of the tool.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e3.2.2 Diffusion wear\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe tool and the workpiece are always in contact during the cutting process, and some alloy elements in the workpiece material diffuse into the tool under the action of high temperature. At the same time, some elements in the tool material will also diffuse into the workpiece material to form mutual diffusion[33,34]. The diffusion behavior of elements can be described by Fick\u0026apos;s law, as shown in Eqs. (1)-(2). This mutual diffusion will reduce the strength of the tool to a certain extent and accelerate the wear of the tool[32]. However, the tool temperature is relatively not large because of the intermittent contact of milling[35], and the cutting time is relatively short in this experiment, so the element diffusion mainly occurs on the tool surface.\u003c/p\u003e\n\u003cp\u003e\u003cimg src=\"data:image/png;base64,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\"\u003e\u003c/p\u003e\n\u003cp\u003e\u003cimg src=\"data:image/png;base64,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\"\u003e\u003c/p\u003e\n\u003cp\u003eWhere is the flux, ,, are diffusion coefficient, concentration of diffusing species and time.\u003c/p\u003e\n\u003cp\u003eFigure\u0026nbsp;14 showed the energy spectrum analysis of the main cutting edge in the experimental group of dry cutting, wet cutting, and optimal parameters experimental group\u0026nbsp;(oil flow 60 ml/h, CO\u003csub\u003e2\u003c/sub\u003e, temperature -50℃). It can be seen from the figure that in addition to the elements C, N, Al, Ti, and W contained in the tool itself, there were also alloy elements such as Fe, Cr, Ni and Si contained in the workpiece material, which showed that the alloy elements in the workpiece material diffuse into the tool. The Fe, Ni, and Co were the congeners, and the diffusion of Ni, Fe, and Cr from the workpiece to the tool was because of the affinity for Co[36,37]. Figure 15 showed the mass percentage of Fe and Cr elements in the local area of the main cutting edge in 8 groups of experiments. It can be found from Fig. 15 that during dry cutting, due to poor cooling and lubrication, the diffusion of Fe and Cr elements was more serious, and the wet cutting experimental group had a better effect in controlling diffusion wear. In addition, the diffusion law of Fe and Cr in other groups was not obvious, and there was a certain element diffusion. Figure 16 was the element distribution diagram of two typical elements Fe and Cr diffused from the workpiece material to the tool. It can be found that the alloy elements such as Fe and Cr diffused from the workpiece material to the tool were relatively enriched in the wear area, indicating that the diffusion wear mainly occurred in the contact and wear area between the tool and the workpiece. There was little difference in the diffusion distribution of elements in the three groups of experiments, and the main difference was still in proportion. Due to the diffusion of elements in the workpiece material, the surface strength of the tool was reduced. In the cutting process, the tool surface with reduced strength was gradually worn, resulting in repeated element diffusion and wear.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e3.2.3 Oxidation wear\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eOxidation wear refers to the chemical reaction between some elements in the tool material and oxygen in the air under the high temperature in the cutting area, resulting in oxides with low strength and hardness. With the progress of cutting, these oxides are taken away by the workpiece and chips, forming wear on the tool surface[38,39]. The mass percentage of the O element on the\u0026nbsp;rake face of the tool in 8 groups of experiments were shown in Fig. 17.\u0026nbsp;It can be found that the mass percentage of the O element was large, indicating that the tool surface was oxidized during cutting. Figure 18 showed the distribution of the O element, it can be seen that the O element was relatively enriched on the tool wear area. By analyzing the mass percentage and\u0026nbsp;distribution of the O element, it can be seen obviously that the optimal parameter array of cryogenic CO\u003csub\u003e2\u003c/sub\u003e-assisted MQL had the best effect on the control of tool oxidation wear. The Co element and WC in the tool substrate material and Ti and Al element in the tool coating reacted with oxygen in the high temperature condition[40]. This oxide was the mixture of Al\u003csub\u003e2\u003c/sub\u003eO\u003csub\u003e3\u003c/sub\u003e, titanium dioxide, and others, which made the tool wear more serious in the process of repeated oxidation and wear.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e3.2.3 Oxidation wear\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eOxidation wear refers to the chemical reaction between some elements in the tool material and oxygen in the air under the high temperature in the cutting area, resulting in oxides with low strength and hardness. With the progress of cutting, these oxides are taken away by the workpiece and chips, forming wear on the tool surface[38,39]. The mass percentage of the O element on the\u0026nbsp;rake face of the tool in 8 groups of experiments were shown in Fig. 17.\u0026nbsp;It can be found that the mass percentage of the O element was large, indicating that the tool surface was oxidized during cutting. Figure 18 showed the distribution of the O element, it can be seen that the O element was relatively enriched on the tool wear area. By analyzing the mass percentage and\u0026nbsp;distribution of the O element, it can be seen obviously that the optimal parameter array of cryogenic CO\u003csub\u003e2\u003c/sub\u003e-assisted MQL had the best effect on the control of tool oxidation wear. The Co element and WC in the tool substrate material and Ti and Al element in the tool coating reacted with oxygen in the high temperature condition[40]. This oxide was the mixture of Al\u003csub\u003e2\u003c/sub\u003eO\u003csub\u003e3\u003c/sub\u003e, titanium dioxide, and others, which made the tool wear more serious in the process of repeated oxidation and wear.\u003c/p\u003e\n\u003cp\u003e\u003cimg src=\"data:image/png;base64,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\"\u003e\u003c/p\u003e\n\u003cp\u003e\u003cimg src=\"data:image/png;base64,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\"\u003e\u003c/p\u003e\n\u003cp\u003eAs shown in Fig. 23, the serrated degree and\u0026nbsp;frequency of dry cutting, wet cutting, and the optimal parameter array were compared. It can be clearly seen that\u0026nbsp;the\u0026nbsp;serrated degree\u0026nbsp;at 5mm and 10mm of the optimal parameter array was the largest, the sawtooth generation frequency\u0026nbsp;of\u0026nbsp;the optimal parameter array\u0026nbsp;was similar to that of the wet cutting and far lower than that of dry cutting at 5mm, and it was the lowest at 10mm. The reason was that the excellent cooling and lubrication conditions make the lower temperature of the cutting area, which led to less plastic deformation region and more fracture region, and resulted in high serrated degree and low\u0026nbsp;frequency[41,44]. And the cutting process was relatively stable [45].\u0026nbsp;\u003c/p\u003e\n\u003cp style=\"text-align: center;\"\u003e\u003cstrong\u003eTable 5\u003c/strong\u003e\u0026nbsp;\u003c/p\u003e\n\u003cp style=\"text-align: center;\"\u003eAnalysis table of serrated degree at 5mm\u003c/p\u003e\n\u003ctable border=\"1\" cellpadding=\"0\" cellspacing=\"0\" width=\"99%\"\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd width=\"17.52577319587629%\"\u003e\n \u003cp\u003eExperience group\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"16.49484536082474%\"\u003e\n \u003cp\u003eAverage sawtooth spacing\u003c/p\u003e\n \u003cp\u003e(mm）\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"16.49484536082474%\"\u003e\n \u003cp\u003eAverage addendum height（mm）\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"16.49484536082474%\"\u003e\n \u003cp\u003eAverage root \u0026nbsp; \u0026nbsp; height\u0026nbsp;\u003c/p\u003e\n \u003cp\u003e(mm）\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"16.49484536082474%\"\u003e\n \u003cp\u003eSerrated degree\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"16.49484536082474%\"\u003e\n \u003cp\u003eFrequency \u0026nbsp;(kHz)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"17.52577319587629%\"\u003e\n \u003cp\u003eExperiment 5\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"16.49484536082474%\"\u003e\n \u003cp\u003e0.166\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"16.49484536082474%\"\u003e\n \u003cp\u003e0.155\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"16.49484536082474%\"\u003e\n \u003cp\u003e0.082\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"16.49484536082474%\"\u003e\n \u003cp\u003e0.471\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"16.49484536082474%\"\u003e\n \u003cp\u003e7.397\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"17.52577319587629%\"\u003e\n \u003cp\u003eDry cutting\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"16.49484536082474%\"\u003e\n \u003cp\u003e0.125\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"16.49484536082474%\"\u003e\n \u003cp\u003e0.121\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"16.49484536082474%\"\u003e\n \u003cp\u003e0.078\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"16.49484536082474%\"\u003e\n \u003cp\u003e0.355\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"16.49484536082474%\"\u003e\n \u003cp\u003e11.201\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"17.52577319587629%\"\u003e\n \u003cp\u003eWet cutting\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"16.49484536082474%\"\u003e\n \u003cp\u003e0.180\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"16.49484536082474%\"\u003e\n \u003cp\u003e0.124\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"16.49484536082474%\"\u003e\n \u003cp\u003e0.080\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"16.49484536082474%\"\u003e\n \u003cp\u003e0.355\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"16.49484536082474%\"\u003e\n \u003cp\u003e6.513\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n\u003c/table\u003e\n\u003cp\u003e\u003cbr\u003e\u003c/p\u003e\n\u003cp style=\"text-align: center;\"\u003e\u003cstrong\u003eTable 6\u003c/strong\u003e\u0026nbsp;\u003c/p\u003e\n\u003cp style=\"text-align: center;\"\u003eAnalysis table of serrated degree at 10mm\u003c/p\u003e\n\u003ctable border=\"1\" cellpadding=\"0\" cellspacing=\"0\" style=\"margin-right: calc(2%); width: 98%;\" width=\"100%\"\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd width=\"17.52577319587629%\"\u003e\n \u003cp\u003eExperience group\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"16.49484536082474%\"\u003e\n \u003cp\u003eAverage sawtooth spacing\u003c/p\u003e\n \u003cp\u003e(mm）\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"16.49484536082474%\"\u003e\n \u003cp\u003eAverage addendum height（mm）\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"16.49484536082474%\"\u003e\n \u003cp\u003eAverage root \u0026nbsp;height\u0026nbsp;\u003c/p\u003e\n \u003cp\u003e(mm）\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"16.49484536082474%\"\u003e\n \u003cp\u003eSerrated degree\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"16.49484536082474%\"\u003e\n \u003cp\u003eFrequency \u0026nbsp;(kHz)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"17.52577319587629%\"\u003e\n \u003cp\u003eExperiment 5\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"16.49484536082474%\"\u003e\n \u003cp\u003e0.175\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"16.49484536082474%\"\u003e\n \u003cp\u003e0.202\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"16.49484536082474%\"\u003e\n \u003cp\u003e0.125\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"16.49484536082474%\"\u003e\n \u003cp\u003e0.381\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"16.49484536082474%\"\u003e\n \u003cp\u003e10.536\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"17.52577319587629%\"\u003e\n \u003cp\u003eDry cutting\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"16.49484536082474%\"\u003e\n \u003cp\u003e0.161\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"16.49484536082474%\"\u003e\n \u003cp\u003e0.199\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"16.49484536082474%\"\u003e\n \u003cp\u003e0.129\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"16.49484536082474%\"\u003e\n \u003cp\u003e0.3\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"16.49484536082474%\"\u003e\n \u003cp\u003e12.778\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"17.52577319587629%\"\u003e\n \u003cp\u003eWet cutting\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"16.49484536082474%\"\u003e\n \u003cp\u003e0.147\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"16.49484536082474%\"\u003e\n \u003cp\u003e0.196\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"16.49484536082474%\"\u003e\n \u003cp\u003e0.134\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"16.49484536082474%\"\u003e\n \u003cp\u003e0.316\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"16.49484536082474%\"\u003e\n \u003cp\u003e13.015\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n\u003c/table\u003e\n\u003cp\u003eIn the secondary deformation zone, a lot of heat was generated due to the adhesion and friction between the chip and the rake face under high pressure, so the temperature of the second deformation zone was high. And the flow stress of the chip materials was decreased because of the thermal softening effect, which resulted in plastic deformation of the chip material near the rake face. Therefore, the state of the second deformation zone can largely reflect the temperature during cutting and the quality of cooling and lubrication, and the width of the second deformation zone was described by , as shown in Fig. 20. The of the three experiments was measured and shown\u0026nbsp;in Fig. 24. It can be found that the of dry cutting at 5mm and 10mm was the largest, it was because of the high temperature during the cutting without the cooling and lubrication, and the flow stress was decreased. It meant that the friction in the second deformation zone was very large, resulting in serious tool wear as shown in Fig. 11. In addition,\u0026nbsp;it can be clearly seen that\u0026nbsp;the of\u0026nbsp;the optimal parameter array at 5mm and 10mm was similar to that of the wet cutting and far lower than that of dry cutting. This indicated that the cutting fluid and cryogenic\u0026nbsp;CO\u003csub\u003e2\u003c/sub\u003e can exchange heat well, and reduce the temperature rise in the second deformation area. In addition, the good lubrication conditions made the friction coefficient and friction force of the tool-chip contact area decrease, and the temperature of tool-chip contact area decreased relatively. Therefore, cutting fluid and cryogenic CO\u003csub\u003e2\u003c/sub\u003e-assisted MQL\u0026nbsp;can improve the adhesion and friction between chip and the tool rake face, which was beneficial to improve tool wear. And it can also found that the cooling and lubrication condition of\u0026nbsp;cryogenic CO\u003csub\u003e2\u003c/sub\u003e-assisted MQL is similar to that of cutting fluid, and the feasibility of the machining application of cryogenic CO\u003csub\u003e2\u003c/sub\u003e-assisted MQL is proved.\u003c/p\u003e\n\u003cp\u003eThe chip thickness of the three experiments was similar at 5mm, and the optimal parameter array of cryogenic CO\u003csub\u003e2\u003c/sub\u003e-assisted MQL at 10mm was the smallest. With the increase of the\u0026nbsp;serrated degree, the chip thickness decreased. At the same time, it was conducive to the separation of chips and played a certain role in improving tool wear.\u003c/p\u003e\n\u003cp\u003eMicrohardness analysis was carried out with a force of 300gf on the non-free surface of chips obtained from the three groups of experiments, and the sampling points were shown in Fig. 25. As shown in\u0026nbsp;Fig. 26,\u0026nbsp;the non-free surface vickers hardness of dry cutting and wet cutting were similar. However, the hardness of the optimal parameter array of cryogenic\u0026nbsp;CO\u003csub\u003e2\u003c/sub\u003e-assisted MQL\u0026nbsp;was the highest. The reason was that during the process of cryogenic\u0026nbsp;CO\u003csub\u003e2\u003c/sub\u003e-assisted MQL,\u0026nbsp;cryogenic CO\u003csub\u003e2\u003c/sub\u003e increased the surface hardness of workpiece materials to a certain extent. When the cryogenic CO\u003csub\u003e2\u003c/sub\u003e temperature was low, the protection effect of cryogenic CO\u003csub\u003e2\u003c/sub\u003e on oil mist was unfavorable. It led to an increase in workpiece surface hardness and poor lubrication, which speeded up the tool wear. However, when the cryogenic CO\u003csub\u003e2\u003c/sub\u003e temperature met the requirements and the oil flow was appropriate, the protection effect of cryogenic CO\u003csub\u003e2\u003c/sub\u003e on oil mist was superior, which made the lubrication effect of the processing area better. Furthermore, the adverse effect on tool wear by the increase of workpiece surface hardness was reduced.\u003c/p\u003e"},{"header":"4 Conclusion","content":"\u003cp\u003eThis study based on the cryogenic CO\u003csub\u003e2\u003c/sub\u003e-assisted MQL, researched the influence mechanism of CO\u003csub\u003e2\u003c/sub\u003e temperature and oil flow on tool wear in the processing of difficult-to-machine materials, analyzed the tool wear mechanism and chip-morphology, and drew the following conclusions.\u003c/p\u003e\n\u003cp\u003e(1) Under the condition of cryogenic CO\u003csub\u003e2\u003c/sub\u003e-assisted MQL, the lower the CO\u003csub\u003e2\u003c/sub\u003e temperature is, the better the improvement effect of tool wear, and there is an optimal value of oil flow. In addition, the lower the temperature of the CO\u003csub\u003e2\u003c/sub\u003e carrier is, the better the protective effect of the oil mist, so that the oil mist can reach the cutting area stably and effectively. Too small oil flow of MQL will lead to oil mist unable to meet the lubrication requirements. Excessive oil flow will lead to the enlargement of oil mist particles, resulting in unfavorable capillary permeation and accessibility of oil mist.\u003c/p\u003e\n\u003cp\u003e(2) Tool wear is mainly adhesive wear, diffusion wear and oxidation wear, and so on. Among the dry cutting, wet cutting, and the optimal parameter array of cryogenic\u0026nbsp;CO\u003csub\u003e2\u003c/sub\u003e-assisted MQL, wet cutting has a better control effect on tool diffusion wear, cryogenic\u0026nbsp;CO\u003csub\u003e2\u003c/sub\u003e-assisted MQL has a better control effect on tool adhesive wear and oxidation wear.\u003c/p\u003e\n\u003cp\u003e(3) The chip of cryogenic\u0026nbsp;CO\u003csub\u003e2\u003c/sub\u003e-assisted MQL is the serrated chip. Compared with dry cutting and wet cutting, the optimal parameter array of cryogenic\u0026nbsp;CO\u003csub\u003e2\u003c/sub\u003e-assisted MQL has a greater degree of the serrated chip, lower\u0026nbsp;frequency,\u0026nbsp;smaller width of the second deformation zone () and\u0026nbsp;smaller thickness, which are conducive to chip breaking and beneficial to improve tool wear. Cryogenic CO\u003csub\u003e2\u003c/sub\u003e increases the surface hardness of the workpiece, but its adverse effect on tool wear can be effectively restrained under appropriate cryogenic CO\u003csub\u003e2\u003c/sub\u003e-assisted MQL.\u003c/p\u003e\n\u003cp\u003e(4) The temperature of the tool-chip contact area is an important factor affecting tool wear. The higher cutting temperature accelerates the progress of adhesive wear, diffusion wear, and oxidation wear, which makes the coating material on the tool surface fall off quickly, forming crater wear, edge collapse, etc, and finally leads to the tool failure. In addition, the higher temperature leads to the high frequency and small serrated degree of chips, larger width of the second deformation zone () and increases the hardness of the non-free surface of the chip which speeds up the wear of the tool.\u003c/p\u003e"},{"header":"Declarations","content":"\u003cp\u003e\u003cstrong\u003eAcknowledgements\u0026nbsp;\u003c/strong\u003eThis work is supported by the Natural Science Foundation of Fujian Province (No. 2020J01066) and the Integration Project of Industry and Research of Fujian Province (No. 2020H6014).\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eFunding\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThis work is supported by the Natural Science Foundation of Fujian Province (No. 2020J01066) and the Integration Project of Industry and Research of Fujian Province (No. 2020H6014).\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eCompeting Interests\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe authors declare that they have no competing interests.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eEthics approval\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eNot applicable.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eConsent to Participate\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eAll authors agree to participate in this study.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eConsent to Publish\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eAll authors agree to publish this paper.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAuthors Contributions\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eFeng Jiang provided ideas and guidance for the paper, Lin Cheng collected and analysed the date, and wrote the paper. Tian Qiu and Shizhan Huang helped collected and analyze the data. Hong Xie and Yan Shui provided experimental support. Chao Liu, Yousheng Li, Liangliang Lin and Zhiyang Xiang provided guidance and advice. Fuzeng Wang, Xian Wu and Lan Yan provided constructive suggestions on the structure and some contents of the paper.\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\n\u003cli\u003eAmiril S A S, Rahim E A, Syahrullail S (2017) A review on ionic liquids as sustainable lubricants in manufacturing and engineering: recent research, performance, and applications. Journal of Cleaner Production, 168:1571-1589. https://doi.org/10.1016/j.jclepro.2017.03.197\u003c/li\u003e\n\u003cli\u003eGajrani K K, Suvin P S, Kailas S V, Sankar M R (2019) Hard machining performance of indigenously developed green cutting fluid using flood cooling and minimum quantity cutting fluid. Journal of Cleaner Production, 206:108-123. https://doi.org/10.1016/j.jclepro.2018.09.178\u003c/li\u003e\n\u003cli\u003eAstakhov V P, (2008) Ecological machining: near-dry machining. Machining: Fundamentals and Recent Advances. Springer London, London, pp 195-223.\u003c/li\u003e\n\u003cli\u003eLawal S A, Choudhury I A, Nukman Y (2012) Application of vegetable oil-based metalworking fluids in machining ferrous metals-a review. International Journal of Machine Tools and Manufacture, 52(1):1-12. https://doi.org/10.1016/j.ijmachtools.2011.09.003\u003c/li\u003e\n\u003cli\u003eHannu T, Suuronen K, Aalto-Korte K, Alanko K, Luukkonen R, J\u0026auml;rvel\u0026auml; M, Jolanki R, Jaakkola M S (2013) Occupational respiratory and skin diseases among finnish machinists: findings of a large clinical study. International Archives of Occupational and Environmental Health, 86(2):189-197. https://doi.org/10.1007/s00420-012-0754-8\u003c/li\u003e\n\u003cli\u003eTan X C, Liu F, Cao H J, Zhang H (2002) A decision-making framework model of cutting fluid selection for green manufacturing and a case study, 129(1-3): 467-470. https://doi.org/10.1016/s0924-0136(02)00614-3\u003c/li\u003e\n\u003cli\u003eLiu Y, Li X J, Qu P X (2012) Research development and application of green cutting technology. Applied Mechanics and Materials, 160:82-86. https://doi.org/10.4028/www.scientific.net/ AMM.160.82 \u003c/li\u003e\n\u003cli\u003eCai C, Liang X, An Q, Tao Z, Ming W, Chen M (2021) Cooling/lubrication performance of dry and supercritical CO\u003csub\u003e2\u003c/sub\u003e-based minimum quantity lubrication in peripheral milling Ti-6Al-4V. International Journal of Precision Engineering and Manufacturing-Green Technology, 8(2):405-421. https://doi.org/10.1007/s40684-020-00194-7\u003c/li\u003e\n\u003cli\u003eDong L, Li C, Zhou F, Bai X, Gao W, Duan Z, Li X, Lv X, Zhang F (2021) Temperature of the 45 steel in the minimum quantity lubricant milling with different biolubricants. The International Journal of Advanced Manufacturing Technology, 113(9-10):2779-2790. https://doi.org/10.1007/s00170-021-06708-0\u003c/li\u003e\n\u003cli\u003eJamil M, Zhao W, He N, Gupta M K, Sarikaya M, Khan A M, R S M, Siengchin S, Pimenov D Y (2021) Sustainable milling of Ti-6Al-4V: a trade-off between energy efficiency, carbon emissions and machining characteristics under mql and cryogenic environment. Journal of Cleaner Production, 281:125374. https://doi.org/10.1016/j.jclepro.2020.125374\u003c/li\u003e\n\u003cli\u003eHeisel U, Schaal M, Wolf G (2009) Burr formation in milling with minimum quantity lubrication. Production Engineering, 3(1):23-30. https://doi.org/10.1007/s11740-008-0138-9\u003c/li\u003e\n\u003cli\u003eGupta M K, Mia M, Singh G, Pimenov D Y, Sarikaya M, Sharma V S (2019) Hybrid cooling-lubrication strategies to improve surface topography and tool wear in sustainable turning of Al 7075-T6 alloy. The International Journal of Advanced Manufacturing Technology, 101(1-4):55-69. https://doi.org/10.1007/s00170-018-2870-4\u003c/li\u003e\n\u003cli\u003eKajaria S, Chittipolu S, Adera S, Hung W N (2012) Micromilling in minimum quantity lubrication. Machining Science and Technology, 16(4):524-546. https://doi.org/10.1080/10910344.2012.730 848\u003c/li\u003e\n\u003cli\u003ePark K, Suhaimi M A, Yang G, Lee D, Lee S, Kwon P (2017) Milling of titanium alloy with cryogenic cooling and minimum quantity lubrication (mql). International Journal of Precision Engineering and Manufacturing, 18(1):5-14. https://doi.org/10.1007/s12541-017-0001-z\u003c/li\u003e\n\u003cli\u003eBeheshti A, Huang Y, Ohno K, Blakey I, Stokes J R (2020) Improving tribological properties of oil-based lubricants using hybrid colloidal additives. Tribology International, 144:106130. https://doi.org/10.1016/j.triboint.2019.106130\u003c/li\u003e\n\u003cli\u003ePereira O, Celaya A, Urbika\u0026iacute;n G, Rodr\u0026iacute;guez A, Fern\u0026aacute;ndez-Valdivielso A, Lacalle L N L D (2020) CO\u003csub\u003e2\u003c/sub\u003e cryogenic milling of Inconel 718: cutting forces and tool wear. Journal of Materials Research and Technology, 9(4):8459-8468. https://doi.org/10.1016/j.jmrt.2020.05.118\u003c/li\u003e\n\u003cli\u003eYıldırım \u0026Ccedil; V (2020) Investigation of hard turning performance of eco-friendly cooling strategies: cryogenic cooling and nanofluid based mql. Tribology International, 144:106127. https://doi.org/10.1016/j.triboint.2019.106127\u003c/li\u003e\n\u003cli\u003eIturbe A, Hormaetxe E, Garay A, Arrazola P J (2016) Surface integrity analysis when machining Inconel 718 with conventional and cryogenic cooling. Procedia Cirp, 45:67-70. https://doi.org/10.1016/j.procir.2016.02.095\u003c/li\u003e\n\u003cli\u003eShokrani A, Dhokia V, Newman S T (2016) Comparative investigation on using cryogenic machining in CNC milling of Ti-6Al-4V titanium alloy. Machining Science and Technology, 20(3):475-494. https://doi.org/10.1080/10910344.2016.1191953\u003c/li\u003e\n\u003cli\u003eYildiz Y, Nalbant M (2008) A review of cryogenic cooling in machining processes. International Journal of Machine Tools and Manufacture, 48(9):947-964. https://doi.org/10.1016 /j.ijmachtools. 2008.01.008\u003c/li\u003e\n\u003cli\u003eLiu M, Li C, Zhang Y, An Q, Yang M, Gao T, Mao C, Liu B, Cao H, Xu X, Said Z, Debnath S, Jamil M, Ali H M, Sharma S (2021) Cryogenic minimum quantity lubrication machining: from mechanism to application. Frontiers of Mechanical Engineering, 16(4):649-697. https://doi.org/10.1007/s11465-021-0654-2\u003c/li\u003e\n\u003cli\u003eK N S R, G M, Anwar S, Rahman M A, Erdi Korkmaz M, Gupta M K, Alfaify A, Mia M (2021) Investigation of surface modification and tool wear on milling nimonic 80A under hybrid lubrication. Tribology International, 155 https://doi.org/10.1016/j.triboint.2020.106762\u003c/li\u003e\n\u003cli\u003eYıldırım \u0026Ccedil; V, Kıvak T, Sarıkaya M, Şirin S (2020) Evaluation of tool wear, surface roughness/topography and chip morphology when machining of Ni-based alloy 625 under mql, cryogenic cooling and cryomql. Journal of Materials Research and Technology, 9(2):2079-2092. https://doi.org/10.1016/j.jmrt.2019.12.069\u003c/li\u003e\n\u003cli\u003eTapoglou N, Lopez M I A, Cook I, Taylor C M (2017) Investigation of the influence of CO\u003csub\u003e2\u003c/sub\u003e cryogenic coolant application on tool wear. Procedia Cirp, 63:745-749. https://doi.org/ 10.1016/j.procir.2017.03.351\u003c/li\u003e\n\u003cli\u003eKhan A M, He N, Li L, Zhao W, Jamil M (2020) Analysis of productivity and machining efficiency in sustainable machining of titanium alloy. Procedia Manufacturing, 43:111-118. https://doi.org/10.1016/j.promfg.2020.02.122\u003c/li\u003e\n\u003cli\u003eMusfirah A H, Ghani J A, Haron C H C (2017) Tool wear and surface integrity of Inconel 718 in dry and cryogenic coolant at high cutting speed. Wear, 376-377:125-133. https://doi.org /10.1016/j.wear.2017.01.031\u003c/li\u003e\n\u003cli\u003eShokrani A, Dhokia V, Newman S T (2012) Environmentally conscious machining of difficult-to-machine materials with regard to cutting fluids. International Journal of Machine Tools \u0026amp; Manufacture, 57:83-101. https://doi.org/10.1016/j.ijmachtools.2012.02.002\u003c/li\u003e\n\u003cli\u003eChaabani S, Rodriguez I, Cuesta M, Ayed Y, Arrazola P J, Germain G, Galdos L, Arrazola P, de Argando\u0026ntilde;a E S, Otegi N, Mendiguren J, Madariaga A, de Buruaga M S (2019) Tool wear and cutting forces when machining Inconel 718 under cryogenic conditions: liquid nitrogen and carbon dioxide. Aip Conference Proceedings, 2113(1) https://doi.org/10.1063/1.5112610\u003c/li\u003e\n\u003cli\u003eHalim N H A, Haron C H C, Ghani J A, Azhar M F (2019) Tool wear and chip morphology in high-speed milling of hardened Inconel 718 under dry and cryogenic CO\u003csub\u003e2\u003c/sub\u003e conditions. Wear, 426-427:1683-1690. https://doi.org/10.1016/j.wear.2019.01.095\u003c/li\u003e\n\u003cli\u003ePereira O, Rodr\u0026iacute;guez A, Fern\u0026aacute;ndez-Abia A I, Barreiro J, L\u0026oacute;pez De Lacalle L N (2016) Cryogenic and minimum quantity lubrication for an eco-efficiency turning of AISI 304. Journal of Cleaner Production, 139:440-449. https://doi.org/10.1016/j.jclepro.2016.08.030\u003c/li\u003e\n\u003cli\u003eAkhtar W, Sun J, Sun P, Chen W, Saleem Z (2014) Tool wear mechanisms in the machining of nickel based super-alloys: a review. Frontiers of Mechanical Engineering, 9(2):106-119. https://doi.org/10.1007/s11465-014-0301-2\u003c/li\u003e\n\u003cli\u003eHao Z, Gao D, Fan Y, Han R (2011) New observations on tool wear mechanism in dry machining Inconel718. International Journal of Machine Tools and Manufacture, 51(12):973-979. https://doi.org/10.1016/j.ijmachtools.2011.08.018\u003c/li\u003e\n\u003cli\u003eMolinari A, Nouari M (2002) Modeling of tool wear by diffusion in metal cutting. Wear, 252(1):135-149. https://doi.org/10.1016/S0043-1648(01)00858-4\u003c/li\u003e\n\u003cli\u003eVereschaka A A, Grigoriev S N, Sitnikov N N, Oganyan G V, Batako A (2017) Working efficiency of cutting tools with multilayer nano-structured Ti-TiCN-(Ti,Al)CN and Ti-TiCN-(Ti,Al,Cr)CN coatings: analysis of cutting properties, wear mechanism and diffusion processes. Surface and Coatings Technology, 332:198-213. https://doi.org/10.1016/j.surfcoat. 2017.10.027\u003c/li\u003e\n\u003cli\u003eDiniz A E, Machado \u0026Aacute; R, Corr\u0026ecirc;a J G (2016) Tool wear mechanisms in the machining of steels and stainless steels. The International Journal of Advanced Manufacturing Technology, 87(9-12):3157-3168. https://doi.org/10.1007/s00170-016-8704-3\u003c/li\u003e\n\u003cli\u003eLiao Y S, Shiue R H (1996) Carbide tool wear mechanism in turning of Inconel 718 superalloy. Wear, 193(1): 16-24. https://doi.org/10.1016/0043-1648(95)06644-6\u003c/li\u003e\n\u003cli\u003eZhang S, Li J F, Deng J X, Li Y S (2009) Investigation on diffusion wear during high-speed machining Ti-6Al-4V alloy with straight tungsten carbide tools. The International Journal of Advanced Manufacturing Technology, 44(1-2):17-25. https://doi.org/10.1007/s00170-008-1803-z\u003c/li\u003e\n\u003cli\u003eHu X, Shao F, Wang R (2020) Wear mechanism of WC-Co cemented carbide tool in cutting Ti-6Al-4V based on thermodynamics. Journal of Wuhan University of Technology-Mater. Sci. Ed., 35(5):973-979. https://doi.org/10.1007/s11595-020-2344-z\u003c/li\u003e\n\u003cli\u003eFan Y, Hao Z, Lin J, Yu Z (2015) New observations on tool wear mechanism in machining Inconel 718 under water vapor + air cooling lubrication cutting conditions. Journal of Cleaner Production, 90:381-387. https://doi.org/10.1016/j.jclepro.2014.11.049\u003c/li\u003e\n\u003cli\u003eNerz J, Kushner B, Rotolico A (1992) Microstructural evaluation of tungsten carbide-cobalt coatings. Journal of Thermal Spray Technology, 1(2):147-152. https://doi.org/10.1007/ BF02659015\u003c/li\u003e\n\u003cli\u003eShi Q, Pan Y, Fu X, Zhou B, Zhang Z (2021) Effect of anisotropy and cutting speed on chip morphology of Ti-6Al-4V under high-speed cutting. The International Journal of Advanced Manufacturing Technology, 113(9-10):2883-2894. https://doi.org/10.1007/s00170-021-06754-8\u003c/li\u003e\n\u003cli\u003eXiong Y, Wang W, Jiang R, Lin K, Shao M (2018) Mechanisms and fem simulation of chip formation in orthogonal cutting in-situ TiB2/7050Al MMC. Materials, 11(4):606. https:// doi.org/10.3390/ma11040606\u003c/li\u003e\n\u003cli\u003eMerchant M E (1945) Mechanics of the metal cutting process. I. Orthogonal cutting and a type 2 chip. Journal of Applied Physics, 16(5):267-275. https://doi.org/10.1063/1.1707586\u003c/li\u003e\n\u003cli\u003eRanjan P, Hiremath S S (2021) Investigation of coated tool performance on the machinability, surface residual stress and chip morphology of martensitic aisi 420 steel. Arabian Journal for Science and Engineering, https://doi.org/10.1007/s13369-021-06303-1\u003c/li\u003e\n\u003cli\u003eSun S, Brandt M, Dargusch M S (2009) Characteristics of cutting forces and chip formation in machining of titanium alloys. International Journal of Machine Tools and Manufacture, 49(7-8):561-568. https://doi.org/10.1016/j.ijmachtools.2009.02.008\u003c/li\u003e\n\u003c/ol\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":false,"highlight":"","institution":"","isAcceptedByJournal":true,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":true,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"the-international-journal-of-advanced-manufacturing-technology","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"jamt","sideBox":"Learn more about [The International Journal of Advanced Manufacturing Technology](https://www.springer.com/journal/170)","snPcode":"170","submissionUrl":"https://submission.nature.com/new-submission/170/3","title":"The International Journal of Advanced Manufacturing Technology","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"em","reportingPortfolio":"Springer Hybrid","inReviewEnabled":true,"inReviewRevisionsEnabled":false},"keywords":"cryogenic CO2, minimum quantity lubrication, tool wear mechanism, serrated chip, high speed milling","lastPublishedDoi":"10.21203/rs.3.rs-1734237/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-1734237/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003eCryogenic CO\u003csub\u003e2\u003c/sub\u003e-assisted minimum quantity lubrication milling technology is a green processing technology with broad application prospects. Aiming at the problem of tool wear in the application of cryogenic CO\u003csub\u003e2\u003c/sub\u003e cooling assisted minimum quantity lubrication in difficult-to-machine materials and the influence of relevant parameters on tool wear, this study used coated cemented carbide tools to perform milling experiments under cryogenic CO\u003csub\u003e2\u003c/sub\u003e-assisted minimum quantity lubrication technology conditions. The micromorphology of the tool rake face and chip was observed, and the energy spectrum of the tool chip contact area was analyzed. The results showed that reducing CO\u003csub\u003e2\u003c/sub\u003e temperature and increasing the oil flow of minimum quantity lubrication can improve the tool wear. The tool wear mechanisms under cryogenic CO\u003csub\u003e2\u003c/sub\u003e-assisted minimum quantity lubrication were mainly abrasive wear, diffusion wear, and oxidation wear. The chip sawtooth degree of the optimal parameter group was more conducive to chip breaking than that of dry cutting and wet cutting groups. The temperature of the tool-chip contact area is an important factor affecting tool wear, the higher the temperature, the faster the tool wear. At the same time, it is verified that cryogenic CO\u003csub\u003e2\u003c/sub\u003e-assisted minimum quantity lubrication technology can replace cutting fluid in hard-to-machine materials under certain conditions.\u003c/p\u003e","manuscriptTitle":"Study on Tool wear mechanism under Cryogenic CO2-Assisted Minimum Quantity Lubrication Technology","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2022-06-15 16:38:37","doi":"10.21203/rs.3.rs-1734237/v1","editorialEvents":[{"type":"communityComments","content":0},{"type":"decision","content":"Major Revisions Needed","date":"2022-10-31T00:47:43+00:00","index":"","fulltext":""},{"type":"reviewerAgreed","content":"","date":"2022-06-10T00:07:02+00:00","index":0,"fulltext":""},{"type":"reviewersInvited","content":"","date":"2022-06-09T13:53:43+00:00","index":"","fulltext":""},{"type":"editorAssigned","content":"","date":"2022-06-09T09:49:20+00:00","index":"","fulltext":""},{"type":"submitted","content":"The International Journal of Advanced Manufacturing Technology","date":"2022-06-07T08:53:50+00:00","index":"","fulltext":""}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"the-international-journal-of-advanced-manufacturing-technology","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"jamt","sideBox":"Learn more about [The International Journal of Advanced Manufacturing Technology](https://www.springer.com/journal/170)","snPcode":"170","submissionUrl":"https://submission.nature.com/new-submission/170/3","title":"The International Journal of Advanced Manufacturing Technology","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"em","reportingPortfolio":"Springer Hybrid","inReviewEnabled":true,"inReviewRevisionsEnabled":false}}],"origin":"","ownerIdentity":"42e8b8d1-b154-44bd-b861-319bd6ee72a2","owner":[],"postedDate":"June 15th, 2022","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"published-in-journal","subjectAreas":[],"tags":[],"updatedAt":"2023-10-16T19:08:26+00:00","versionOfRecord":{"articleIdentity":"rs-1734237","link":"https://doi.org/10.1007/s00170-023-11122-9","journal":{"identity":"the-international-journal-of-advanced-manufacturing-technology","isVorOnly":false,"title":"The International Journal of Advanced Manufacturing Technology"},"publishedOn":"2023-02-28 19:03:02","publishedOnDateReadable":"February 28th, 2023"},"versionCreatedAt":"2022-06-15 16:38:37","video":"","vorDoi":"10.1007/s00170-023-11122-9","vorDoiUrl":"https://doi.org/10.1007/s00170-023-11122-9","workflowStages":[]},"version":"v1","identity":"rs-1734237","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-1734237","identity":"rs-1734237","version":["v1"]},"buildId":"_2-kVJe1T_tPrBINL-cwx","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}