Re-Imagining Additive Manufacturing through Multi-Material Laser Powder Bed Fusion

Re-Imagining Additive Manufacturing through Multi-Material Laser Powder Bed Fusion | 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 Article Re-Imagining Additive Manufacturing through Multi-Material Laser Powder Bed Fusion Jacklyn Griffis, Kazi Shahed, Kenneth Meinert, Buket Yilmaz, Matthew Lear, and 1 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-4301742/v1 This work is licensed under a CC BY 4.0 License Status: Posted Version 1 posted You are reading this latest preprint version Abstract Multi-Material Laser Powder Bed Fusion (MM-LPBF) offers a novel approach for fabricating high-resolution components with both spatially tailored material properties and design by capitalizing on selective powder deposition (SPD) in conventional laser powder bed fusion (LPBF) processing. Advancements in multi-material additive manufacturing (AM), specifically MM-LPBF is now presenting a unique opportunity to reimagine additive manufacturing as we know today in terms of the local material assignment, AM-processing induced properties and design complexity which can help achieve functional requirements across multiple length scales. In this study, new MM-LPBF capability to manufacture a sheet-based gyroid structure composed of 904L stainless steel and bronze (CuSn10) is studied for unique MM-LPBF signatures (e.g., melt pool characteristics, grain morphology and mechanical properties via intermittent micro-CT during flexural testing). The fracture mechanics of complex multi-material structures is investigated through multi-scale domain techniques, including mechanical testing (supported by digital image correlation (DIC), finite element analysis (FEA), and intermittent micro-CT), microstructural and morphological characterization of the bimaterial interface. This study analyzes the contribution of factors such as thermomechanical material compatibility, process-induced defects, cracking, porosity, and microstructure to determine the ultimate origin of failure and propagation patterns. Interface formation mechanisms are explored to elucidate process-structure-property framework for MM-LPBF. Findings from this study clearly demonstrate both the opportunity of MM-LPBF and current technological challenges to further advance the adoption of MM-LPF for a wide range of applications such as thermo-fluidic surfaces, solid-state energy storage, and biodegradable implants, among others. Physical sciences/Engineering Scientific community and society/Business and industry/Engineering Additive manufacturing bi-metallic interface formation multi-material laser powder bed fusion selective powder deposition triply periodic minimal surfaces Figures Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 Figure 7 1. INTRODUCTION Multi-material laser powder bed fusion (MM-LPBF) is an evolving advanced manufacturing capability for spatially graded architectures, enabling the variation of mechanical, thermal, and other properties based on functional requirements 1 . As shown in Fig. 1 , selective powder deposition (SPD) recoating provides reliable means of depositing multiple materials based on 3D computer aided design (CAD) model (up to three powders) within controlled regional portions of the build plate 2 . Each material region is selectively fused with laser processing conditions that are tailored to each material on a layer-by-layer basis. Recent advancements in multi-material additive manufacturing techniques have significantly addressed the previous monolithic design challenge in L-PBF by enabling spatially tailored parts for functional requirements 3 . Although such approaches have gained significant attention in manufacturing research, they have been largely hindered by the ability to truly achieve concurrent design and manufacturing of multi-material AM as shown in Fig. 1 . Both the engineering and scientific community has always been intrigued by the self-evident observations in various biological systems and manufacturing-dependent industries, ranging from nanometer-scale applications like solar energy cell sheet layering 4 to MM metal-composite aviation engine blades 5 . For instance, multiple natural occurrences leverage a difference in stiffness between materials to provide a structural core or protective shell, paired with a flexible, non-load bearing material for secondary supporting function 6,7 . The ability to concurrently design and manufacture highly complex multi-material structures is of high interest for a wide range of applications such as: high temperature surface fluidic structures 8 , solid state energy devices 9,10 , biomedical AM implants with functional surfaces 11 , and corrosion resistant graded components 12 . In order to demonstrate the unique capability to simultaneously design and manufacture highly complex structures in multi-material within a single 3D geomoetry, this study leverages triply periodic minimal surfaces (TPMS), which are characterized by a smooth continuous surface, interconnected porosity, and zero mean curvature 13 . TPMS structures offer similar mechanical properties to solid traditionally manufactured parts with reduced weight and material consumption 14 . Among various TPMS topological classes, the sheet-based gyroid structure has shown promise for biomedical applications due to its high surface area-to-volume ratio and tortuosity, which enhances bone-to-implant contact area and bone ingrowth and limit stress-shearing that arises due to the large stiffness difference between traditional implants and human bone 15 . TPMS structures have also found applications in tissue engineering 16–19 , construction 20,21 , electrical 22 , acoustic 23 , transportation 24 , chemical 25 , optical 26 , and energy 27,28 industries. The unique design features of TPMS, including pore size control 29,30 , functional grading capability 31,32 , high surface area-to-volume ratio 33 , high strength combined with low stiffness 34 , and favorable fluid dynamic characteristics 35 , have attracted significant interest in recent years. Recent efforts in metal-based AM processes that are capable of multi-material functional gradation include directed energy deposition (DED), which has poor part feature resolution and surface finish and require substantial post-AM re-surfacing and post-processing, such as machining 36 . This makes manufacturing of complex geometries such as TPMS structures difficult, if not impossible. Other state-of-the-art AM processing such as Wire Arc Additive Manufacturing (WAAM) cannot achieve both complex design and multi-material capabilities 37 . The emergence of MM-LPBF capabilities presented in this work allows for a new range of precision in advanced manufacturing of complex structures (e.g., TPMS) with high-precision volumetric selective placement of multi-materials which could also help address the application-driven latency into industries requiring multi-functional AM capabilities at higher resolution than existing methods via DED techniques. While the motivation for multi-material AM processing is well documented 8,38,39 , there is a lack of understanding into the effects of processing conditions on resulting material characteristics (e.g., melt pool morphology, microstructure morphology, and AM-process induced defects), and the resulting mechanical response (e.g., strength and fracture mechanisms) in MM-LPBF. Prior studies have predominantly focused on single alloy in L-PBF and have not fully leveraged the new geometrical freedom and resolution offered by selective powder deposition in LPBF systems beyond manual switching over of secondary metal to print bimetallic bulk specimens 40–43 . In summary, the motivation for this research lies in the critical need to better understand the processing science of MM-LPBF to avoid prevailing AM processing defects, such as porosity, cracking, and material cross-contamination to accelerate advancements and adoption of MM-LPBF manufacturing technique 39,44 . To the best of author’s knowledge, this is the first study focused on understanding the manufacturing and resulting performance of multi-material TPMS that can now be realized through MM-LPBF. Based on previous work in multi-material AM through DED, it is hypothesized that failure will originate and propagate through the material with the lowest yield strength. The origin and propagation of failure of a sheet-based gyroid specimen manufactured of 904L stainless steel and bronze (CuSn10) via MM-LPBF under three-point flexural testing is examined. As detailed in the Materials and Methods Supplementary document, this study also presents a comprehensive analysis on fracture behavior, and constituent material compatibility across the fusion zone in MM-LPBF by employing digital image correlation (DIC) coupled with finite element analysis (FEA), electron backscatter dispersion spectroscopy (EBSD), and microcomputed tomography (MCT) to understand the effects of as-built defects on mechanical performance in MM-LPBF manufacturing. Additional analysis of as-built cracking and porosity defects and fusion zone microstructure imply a joint contribution of thermomechanical material disparity and material incompatibility at the given machine parameters. 2. RESULTS 2.1. Microstructural Characterization Witness coupons of four material orientations were fabricated through MM-LPBF (Fig. 3 ) to understand the influence of fusion plane and material compatibility with respect to the processing conditions. As shown in Fig. 2 , AM process induced cracks that were parallel to the fusion plane was evident in all the orientations except Bronze on Stainless Steel (SS, Br)z. Results obtained from EBSD and scanning electron microscopy (SEM) analyses provide insight into the crack patterns and their underlying causes. Within the various degrees of cracking, all severe as-built defects occurred on the steel side of the fusion plane. The root of nano-scale cracking occurs at the interface between the fusion zone and the steel and extends perpendicular to the fusion plane like dendritic growth as shown in Fig. 3 . The cause of this cracking could be attributed to a mismatch in thermophysical properties across a discrete material change while sintering. This pattern of cracking was also observed in other material orientations (Br, SS)y, (SS, Br)z, and (Br, SS)z as shown in Fig. 3 where similar microstructure across all three scanned regions and similar process-induced defects at the fusion plane were observed. This indicates that the direction of recoating blade in selective powder deposition does not impact the resultant microstructure and defect formation at the multi-material interface. EBSD analysis of specimen (Br, SS)z reveals micro-scale cracking present strictly within the stainless-steel grain structures as shown in Fig. 2 . Grain structure at the fusion plane suggests that the higher energy density used to process SS caused unstable re-melting of the bronze, resulting in severe defects as shown in Fig. 3 . and an elongated interface, in comparison to the other three orientations. EBSD of all four orientations show grain refinement at the fusion zone as a defining feature of the interface which clearly reflects the higher cooling rate in MM-LPBF due to the heterogenous mixing of alloying elements. It should be observed that lack of AM process induced cracks with complete fusion were observed in one orientation (SS, Br)z. Nondestructive evaluation and thermomechanical simulation of these specimens has demonstrated a preferential material orientation along the build direction (SS, Br)z when compared to (Br, SS) 2 . It is evident that orientation of material sections, as well as dissimilarities in thermal material properties and energy input required to reach their solidification temperature play concurrent roles in thermal build history and thus, thermally induced residual stress and crack formation. This effect needs to be further studied by including the effects of unmelted powders and sacrificial support structures in underlying layers because the thermal stress on part geometry during MM-LPBF would be impacted by the differences in thermal conductivity of the different powders in this advanced manufacturing process. 2.2. EDS Investigation for elemental diffusion and melt pool morphology Energy dispersive spectroscopy (EDS) analysis of witness cube (Br, SS)y revealed an elongated "blowout" region of copper contaminates lateral to the recoating direction. This cube's fusion plane was positioned parallel to the recoating blade trajectory during the additive manufacturing process. The selective powder deposition process involves two key steps, ( 1 ) the powder drums which deposit a 150–200 \(\mu m\) layer of powder, according to the 2D slicing geometry, and ( 2 ) a suction and skiving blade which cuts that layer of powder down to a layer height appropriate for sintering (40–50 \(\mu m\) ). It was presumed that the movement of the skive across the powder layer could disturb the accuracy of the selective powder deposition chamber within the XY plane. The presence of this localized copper contamination, shown in the EDS of cube (Br, SS)y, suggests the possibility that the skive blade may have played a role in spreading copper particles as it cuts across the build volume. Micron-scale cracking within (Br, SS)z has allowed for unmelted bronze powder to become trapped. This cracking was observed to continue around the entire circumference and extend a few millimeters into the cube. No other specimen was observed to have cracking severe enough to trap powder. Cubes (Br, SS)y and (SS, Br)x presented similar cracking in scale, however (Br, SS)y observed a more elongated region of cracking extending from the fusion plane. This was attributed to the contamination of bronze powder into the steel region, leading to more severe copper contamination cracking. Cracking from these specimens originates at the steel-interface region and extends deeper into the steel. These dendritic cracks then connect laterally, with more nano-scale cracking observed parallel to the fusion plane. These cracks are evidence of residual process-induced stress build up. Notably, cube (SS, Br)z (bronze sintered over steel) exhibited no nano- or micron-scale cracking. EDS shows a depth of penetration sufficient to diffuse the first copper layer into the steel substrate, however a few instances of circular bronze particles at the interface suggest partial melting. 2.3. Mechanical Testing 2.3.1. Intermittent Micro-CT The intermittent micro-CT process involved the repeated plastic deformation of the specimens, followed by successive micro-CT scans to capture the deformation of the gyroid’s internal structure as failure progressed. This iterative approach was performed three times to document the stages leading to failure. While the resolution of micro-CT is not sufficient to observe the nano- and micron-scale cracking shown in EBSD and EDS, the intermittent micro-CT revealed that the location of failure initiation was consistent with the location of these cracks. The ultimate mode of failure was characterized by the delamination of the two material sections. Figure 7 shows that cracks which lead to failure propagate from the interface region, and initially extend perpendicular to the fusion zone, into the steel region. These cracks then join along the interface until delamination of the bronze and steel regions is observed. 2.3.2. Digital Image Correlation with Preliminary FEA The presented preliminary FEA simulations enabled the comparison of experimental and simulated strain values and introduced a method to determine the stress distribution across the specimen. Figure 5 presents a comparative analysis of the FEA and DIC results at three distinct points along the elastic deformation progression, where the final displacement of 3 mm signifies the experimental yielding point. The simulated load at the experimental yielding displacement is within 12% of the measured experimental load. FEA simulation allows the determination of the stress across the specimen, which is otherwise unachievable using experimental or analytical methods. These simulated stress values provided additional context for understanding the material response under load, particularly with respect to the onset of yielding. At the experimental yield displacement, the simulation indicates a Von Mises stress magnitude consistent with failure within bronze material sections. Additionally, the FEA indicates that the experiential beams consistently fail at a lower load than what is computationally expected. This indicates that, in combination with the intermittent micro-CT results, the as-built nano- and micron-scale cracking near the interface leads to premature failure. In this context, premature failure should be defined as yielding in a material region which is not consistent with the material of the lowest ultimate tensile strength (UTS). 3. DISCUSSION Interfacial Distribution of Elements and mechanisms of melt pool formation Several process-driven factors influence the interfacial distribution of elements in parts manufactured using MM-LPBF. Contributing factors are critical to identify and understand to limit, or predict defect formation, and interfacial morphology. LPBF, especially compared to traditional welding processes, boasts significantly higher cooling rates (up to \({10}^{7}\frac{mm}{s},\) compared to \({10}^{3}\frac{mm}{s}-{10}^{4}\frac{mm}{s}\) ). Rapid cooling is exacerbated in steel regions adjacent to the interface due to the high thermal conductivity of copper alloys. Higher cooling rates in metals are known to microstructural grain refinement 45–47 . The effects of rapid solidification are clear in the EBSD scan across all four-witness cube’s fusion zones shown in Fig. 2 . The EBSD shows that the interfacial grain structure is significantly smaller than that of either constituent material. These ultrafine grains are characteristic of rapid cooling during the LPBF process 47,48 . The ‘dilution effect,’ analogous to that observed in cladding operations 49–51 , is clearly observed both in the EDS of Fe-Cu distribution across the interface, and in the optical image (Fig. 3 ). This analogy is only relevant for the two witness coupons ((SS, Br)z, and Br, SS)z) in which the interfacial plane is parallel to the build plate. As multiple layers of a secondary material are deposited over a substrate of a primary material, the utmost layer of the primary material remelts into the newest layer as the secondary material is sintered on top. This region forms the visual ‘interface,’ which is characterized by a higher chemical composition of elements from both alloys, and a clear region of grain refinement. With subsequent layers, the distribution of the primary material becomes negligible. The mechanism driving the diffusion of elements includes a highly turbulent melt pool and conductive forces within the melt pool. Marangoni convection in the melt pool is the main active force describing the melting of powder and the mass/heat transfer throughout the pool 52 . Marangoni convection causes the circular swirling of both molten metals within the melt pool. This is visually evident post-solidification in Fig. 6 . This, in combination with gravitational forces acting on materials of varying density and material-wise energy density differences lead to a heterogeneous material distribution throughout the interface. Regions of Fe-rich and Cu-rich regions are present for all four material orientations and are denoted in Fig. 3 . As-build cracking near the interface was observed to be dependent on material orientation. Identified contributing factors are three-fold: ( 1 ) The physical mismatch in thermal material properties between materials leads to inconsistent thermal expansion and contraction under the same thermal loads. ( 2 ) While printing steel over bronze, the expected energy absorption from the bronze substrate is much higher than what is expected for fusing steel over a steel substrate due to the high thermal conductivity of copper alloys. This condition is akin to processing steel at a lower energy density than is recommended by most manufactures. Defects associated with the low energy density processing of steel include major and minor porosity and micro-cracking 53–55 , both of which are present in the optical images of Fig. 3 . ( 3 ) Copper contamination within austenitic steel weldments can lead to the formation of cracking between steel grain boundaries. Copper contamination cracking (CCC) 56,57 occurs as copper is introduced to the heat-affected zone and leads to the diffusion of copper along/between the steel grain boundaries during solidification. This is consistent with the EDS results in Fig. 3 , showing the copper contamination within into the steel cracks, approximately 150 \(\mu m\) away from the interface. 3.1. Mechanical Testing Intermittent micro-CT was performed in the investigation into the failure mechanisms and material behavior for multi-material TPMS components. This method provides insights into the origin and progression of failure, and when coupled with DIC, the distribution of strains, and the identification of key factors influencing structural integrity. Figure 7 shows that cracks which lead to failure originate from the regions which contain nano- and micron-scale cracking (Fig. 2 , 3 ). Visual inspection of the fractured regions showed steel on both opened sides of the cracks, substantiating the fact that failure occurred solely within the steel portion because of as-build defects and cracking. The origin of crack propagation is consistent with the location of the micro- and nano-scale cracking in Fig. 3 . Provided mechanical failure has been shown to have occurred prematurely according to FEA simulation, it is theorized that these sub-scale cracks were the cause for failure. Superficial defects in AM have been shown to have massive adverse effects on cyclical loading in fatigue failure, especially compared to static loading 58–60 . These findings emphasize the importance of as-built defect mitigation in multi-material LPBF processes, as these defects can serve as critical stress concentration points leading to premature structural failure. 3.1.1. Digital Image Correlation with Preliminary FEA The strain maps obtained from both FEA and DIC exhibit fair agreement concerning the distribution of strain across the MSMG specimen. This initial agreement between the FEA and DIC suggests that finite element simulation is effective in capturing preliminary deformation characteristics. Notwithstanding the overall agreement, there are targeted areas where the DIC strain maps show elevated positive strain. These disparities can be attributed to premature failure events. The regions are solely located within the steel section adjacent to the fusion zone. Premature failure indicates that factors other than material strength played a dominant role in the failure mechanism such as thermomechanically induced defects or poor alloying combinations. These findings align with the physical manifestation of as-built cracking in the same vicinity. Despite the areas of discrepancy mentioned above, the agreement between the preliminary FEA and DIC strain maps underscores the capability of FEA to effectively simulate multi-material LPBF complex structures. However, it is crucial to complement FEA with experimental techniques like DIC to validate and verify simulation results, particularly in cases where localized material behavior and premature failures are of concern. Continued efforts towards calibrating and verifying this FEA model will be used to inform future design work using MM-LPBF of complex geometries. 3.2. Mitigating Thermomechanical Induced Defects As apparent in EBSD images at the fusion zone (Fig. 2 ) and as indicated by the premature failure in mechanical testing (Fig. 7 ), as-build defects seen at the fusion plane are severe and detrimental to mechanical strength. Previous work has indicated thermally induced strains concentrated at the fusion plane due to a dissimilarity in thermal expansion and conduction 2 . Future research efforts should focus on reducing thermal gradients at the fusion plane to eliminate thermal strain concentration. A combination of applied controls theory for novel laser scanning strategy and in-situ process monitoring should aim towards maintaining uniform thermal expansion across the fusion plane 61 . Leveraging multi-laser LPBF systems may provide additional flexibility in scanning strategy design and thermal history control. Further investigation into other compatible metallic powder bed systems (e.g., electron beam melting (EBM)) is warranted to expand the MMAM application of SPD. 4. CONCLUSION The advent of multi-material metal fabrication through LPBF has opened a new advanced manufacturing with concurrent design freedom of structural design, local material assignment which could allow engineers and designers to push boundaries on modern manufacturing. This study has demonstrated the while MM-LPBF enables the creation of complex, multifunctional components the state-of-art knowledge in single material LPBF needs to be reimagined to account for interaction across multiple length scales. 1. Defects observed at the interface of parts fabricated through MM-LPBF are shown to be highly dependent on material orientation with respect to the build direction. 2. Cracking and defects, which occur solely between the interfacial region and 904L SS, are attributed to a mismatch in thermophysical properties, differences in volumetric energy density (VED) for alloy-specific processing condition, and copper contamination cracking. 3. Rapid solidification, Marangoni convection and the ‘dilution’ effect are the main mechanisms behind elemental diffusion within the interface. 4. The melting of a material processed with a high VED over a material processed with a low VED leads to hydrodynamic instability in the melt pool, and an elongated interface. 5. The mechanical testing of complex structures reveals premature failure which originates from nano- and micron-scale cracking near the interface, when compared to FEA simulation. The utilization of thermomechanical simulation and in-situ process monitoring emerges as essential Integrated Computational Materials Engineering (ICME) tools to provide predictive insights into thermal build-up for optimized parameter selection in MM-LPBF. In addition, design methods of MM-LPBF structures and build preparation (e.g., build orientation, leveraging multi-material for dissolvable supports and/or This study not only highlights existing challenges in MM-LPBF but also lays the groundwork for generating in-situ data-driven modeling methods for advanced predictive parameter selection. In addition, design methods of MM-LPBF structures and build preparation (e.g., build orientation, multi-material for dissolvable supports and/or directional heat transfer), and leveraging in-situ processing monitoring to understand melt pool dynamics will be required in future studies. In summary, this study not only highlights existing challenges in MM-LPBF but also lays the groundwork for generating in-situ data-driven modeling methods for advancing materials processing map predictive parameter selection. Declarations Data Availability The data supporting this study's findings are available from the corresponding author upon reasonable request. Author Contribution J.G. is credited with concept generation, data analysis and leading the manuscript preparation with contributions from all authors. K.S. and K.M. performed micro-CT numerical analysis and optical characterization. B.Y. helped with the original draft. M.L. supervised and advised on FEA simulation. G.M. contributed towards concept generation, funding, editing and overall supervision. Acknowledgement The authors acknowledge the Applied Research Laboratory at Pennsylvania State University for their support and contributions through the Walker Graduate Assistantship. References Zheng, Y., Zhang, W., Lopez, D. M. B. & Ahmad, R. Scientometric analysis and systematic review of multi-material additive manufacturing of polymers. Polymers 13, (2021). Griffis, J. C., Shahed, K. S., Okwudire, C. E. & Manogharan, G. P. PROCESS MODELING OF MULTI-MATERIAL LASER POWDER BED FUSION. in Solid Freeform Fabrication 2023 (2023). Bandyopadhyay, A. & Heer, B. Additive manufacturing of multi-material structures. Mater. Sci. Eng. R Rep. 129, 1–16 (2018). Das, S. Using Nanotechnology to Make Solar Cells Cheaper and More Efficient. AZO Cleantech (2019). Gardiner, G. Developing next-gen, smart engine composite fan blades. https://www.compositesworld.com/news/developing-next-gen-smart-engine-composite-fan-blades (2024). Białkowski, J. et al. Evolution, types, and distribution of flight control devices on wings and elytra in bark beetles. Sci. Rep. 14, 6999 (2024). Stelzner, J., Million, S., Stelzner, I., Nelle, O. & Banck-Burgess, J. Micro-computed tomography for the identification and characterization of archaeological lime bark. Sci. Rep. 13, 6458 (2023). Binder, M. et al. Potentials and Challenges of Multi-Material Processing by Laser-Based Powder Bed Fusion. (2018) doi: 10.26153/TSW/17025 . Tian, X. & Zhou, K. Additive Manufacturing of Energy Storage Devices. in Additive Manufacturing: Materials, Functionalities and Applications (ed. Zhou, K.) 51–83 (Springer International Publishing, Cham, 2023). doi: 10.1007/978-3-031-04721-3_2 . Cheng, M. & Jiang, Y. 3D-printed solid-state electrolytes for electrochemical energy storage devices. J. Mater. Res. 36, 4547–4564 (2021). Bartolomeu, F., Costa, M. M., Alves, N., Miranda, G. & Silva, F. S. Additive manufacturing of NiTi-Ti6Al4V multi-material cellular structures targeting orthopedic implants. Opt. Lasers Eng. 134, 106208 (2020). Pütz, R. D. et al. Microstructure and Corrosion Behavior of Functionally Graded Wire Arc Additive Manufactured Steel Combinations. Steel Res. Int. 92, 2100387 (2021). Feng, J., Fu, J., Yao, X. & He, Y. Triply periodic minimal surface (TPMS) porous structures: from multi-scale design, precise additive manufacturing to multidisciplinary applications. Int. J. Extreme Manuf. 4, 022001 (2022). Qu, S. et al. High-precision laser powder bed fusion processing of pure copper. Addit. Manuf. 48, 102417 (2021). Tilton, M., Borjali, A., Isaacson, A., Varadarajan, K. M. & Manogharan, G. P. On structure and mechanics of biomimetic meta-biomaterials fabricated via metal additive manufacturing. Mater. Des. 201, 109498 (2021). Yoo, D. J. Computer-aided porous scaffold design for tissue engineering using triply periodic minimal surfaces. Int. J. Precis. Eng. Manuf. 12, (2011). Zhang, X. Y., Fang, G., Xing, L. L., Liu, W. & Zhou, J. Effect of porosity variation strategy on the performance of functionally graded Ti-6Al-4V scaffolds for bone tissue engineering. Mater. Des. 157, (2018). Zhianmanesh, M., Varmazyar, M. & Montazerian, H. Fluid Permeability of Graded Porosity Scaffolds Architectured with Minimal Surfaces. ACS Biomater. Sci. Eng. 5, 1228–1237 (2019). Li, L. et al. Early osteointegration evaluation of porous Ti6Al4V scaffolds designed based on triply periodic minimal surface models. J. Orthop. Transl. 19, 94–105 (2019). Al-Ketan, O., Rowshan, R. & Abu Al-Rub, R. K. Topology-mechanical property relationship of 3D printed strut, skeletal, and sheet based periodic metallic cellular materials. Addit. Manuf. 19, (2018). Yan, C. et al. Evaluation of light-weight AlSi10Mg periodic cellular lattice structures fabricated via direct metal laser sintering. J. Mater. Process. Technol. 214, 856–864 (2014). Torquato, S. & Donev, A. Minimal surfaces and multifunctionality. Proc. R. Soc. Math. Phys. Eng. Sci. 460, 1849–1856 (2004). Abueidda, D. W., Jasiuk, I. & Sobh, N. A. Acoustic band gaps and elastic stiffness of PMMA cellular solids based on triply periodic minimal surfaces. Mater. Des. 145, (2018). Liverani, E., Lutey, A. H. A., Fortunato, A. & Ascari, A. Characterization of lattice structures for additive manufacturing of lightweight mechanical components. ASME 2017 12th Int. Manuf. Sci. Eng. Conf. MSEC 2017 Collocated JSMEASME 2017 6th Int. Conf. Mater. Process. 2, 1–8 (2017). Thomas, N. et al. 3D printed spacers based on TPMS architectures for scaling control in membrane distillation. J. Membr. Sci. 581, (2019). Turner, M. D. et al. Miniature chiral beamsplitter based on gyroid photonic crystals. Nat. Photonics 7, (2013). Peng, H., Gao, F. & Hu, W. Design, modeling and characterization of triply periodic minimal surface heat exchangers with additive manufacturing. in Solid Freeform Fabrication 2019: Proceedings of the 30th Annual International Solid Freeform Fabrication Symposium - An Additive Manufacturing Conference, SFF 2019 (2019). Kim, J. & Yoo, D. J. 3D printed compact heat exchangers with mathematically defined core structures. J. Comput. Des. Eng. 7, (2020). Vijayavenkataraman, S., Zhang, L., Zhang, S., Fuh, J. Y. H. & Lu, W. F. Triply periodic minimal surfaces sheet scaffolds for tissue engineering applications: An optimization approach toward biomimetic scaffold design. ACS Appl. Bio Mater. 1, 259–269 (2018). Walker, J. M. et al. Design and mechanical characterization of solid and highly porous 3D printed poly(propylene fumarate) scaffolds. Prog. Addit. Manuf. 2, (2017). M. Afshar, A. Pourkamali Anaraki, H. Montazerian, J. K. Additive manufacturing and mechanical characterization of graded porosity scaffolds designed based on triply periodic minimal surface architectures. J. Mech. Behav. Biomed. Mater. (2016). Afshar, M., Pourkamali Anaraki, A. & Montazerian, H. Compressive characteristics of radially graded porosity scaffolds architectured with minimal surfaces. Mater. Sci. Eng. C 92, 254–267 (2018). Yang, S. D., Lee, H. G. & Kim, J. A phase-field approach for minimizing the area of triply periodic surfaces with volume constraint. Comput. Phys. Commun. 181, (2010). Kapfer, S. C., Hyde, S. T., Mecke, K., Arns, C. H. & Schröder-Turk, G. E. Minimal surface scaffold designs for tissue engineering. Biomaterials 32, 6875–6882 (2011). Castro, A. P. G., Pires, T., Santos, J. E., Gouveia, B. P. & Fernandes, P. R. Permeability versus design in TPMS scaffolds. Materials 12, (2019). Ghanavati, R., Naffakh-Moosavy, H., Moradi, M. & Eshraghi, M. Printability and microstructure of directed energy deposited SS316l-IN718 multi-material: numerical modeling and experimental analysis. Sci. Rep. 12, 1–16 (2022). Hauser, T. et al. Multi-Material Wire Arc Additive Manufacturing of low and high alloyed aluminium alloys with in-situ material analysis. J. Manuf. Process. 69, 378–390 (2021). Wei, C. & Li, L. Recent progress and scientific challenges in multi-material additive manufacturing via laser-based powder bed fusion. Virtual Phys. Prototyp. 16, 347–371 (2021). Nazir, A. et al. Multi-material additive manufacturing: A systematic review of design, properties, applications, challenges, and 3D printing of materials and cellular metamaterials. Mater. Des. 226, 111661 (2023). Liu, Z. H., Zhang, D. Q., Sing, S. L., Chua, C. K. & Loh, L. E. Interfacial characterization of SLM parts in multi-material processing: Metallurgical diffusion between 316L stainless steel and C18400 copper alloy. Mater. Charact. 94, 116–125 (2014). Sing, S. L., Lam, L. P., Zhang, D. Q., Liu, Z. H. & Chua, C. K. Interfacial characterization of SLM parts in multi-material processing: Intermetallic phase formation between AlSi10Mg and C18400 copper alloy. Mater. Charact. 107, 220–227 (2015). Chen, J. et al. Interfacial microstructure and mechanical properties of 316L /CuSn10 multi-material bimetallic structure fabricated by selective laser melting. Mater. Sci. Eng. A 752, 75–85 (2019). Zhang, M., Yang, Y., Wang, D., Song, C. & Chen, J. Microstructure and mechanical properties of CuSn/18Ni300 bimetallic porous structures manufactured by selective laser melting. Mater. Des. 165, 107583 (2019). Han, D. & Lee, H. Recent advances in multi-material additive manufacturing: methods and applications. Curr. Opin. Chem. Eng. 28, 158–166 (2020). Liu, S. et al. Effect of Cooling Rate on Microstructure and Grain Refining Behavior of In Situ CeB6/Al Composite Inoculant in Aluminum. Metals 7, 204 (2017). Ali, M. et al. Effect of cooling rate and composition on microstructure and mechanical properties of ultrahigh-strength steels. J. Iron Steel Res. Int. 26, 1350–1365 (2019). Keshavarzkermani, A. et al. An investigation into the effect of process parameters on melt pool geometry, cell spacing, and grain refinement during laser powder bed fusion. Opt. Laser Technol. 116, 83–91 (2019). Pathania, A., Subramaniyan, A. K. & Nagesha, B. K. Influence of post-heat treatments on microstructural and mechanical properties of LPBF-processed Ti6Al4V alloy. Prog. Addit. Manuf. 7, 1323–1343 (2022). Hemmati, I., Ocelík, V. & De Hosson, J. Th. M. Dilution effects in laser cladding of Ni–Cr–B–Si–C hardfacing alloys. Mater. Lett. 84, 69–72 (2012). Liu, K., Li, Y., Wang, J. & Ma, Q. Effect of high dilution on the in situ synthesis of Ni–Zr/Zr–Si(B, C) reinforced composite coating on zirconium alloy substrate by laser cladding. Mater. Des. 87, 66–74 (2015). Zhu, S., Chen, W., Zhan, X., Ding, L. & Wang, E. Optimization of dilution rate of laser cladding repair based on deep learning. Int. J. Adv. Manuf. Technol. 110, 1471–1484 (2020). Cox, B., Ghayoor, M., Pasebani, S. & Gess, J. Tracking of Marangoni driven motion during laser powder bed fusion. Powder Technol. 425, 118610 (2023). Choo, H. et al. Effect of laser power on defect, texture, and microstructure of a laser powder bed fusion processed 316L stainless steel. Mater. Des. 164, 107534 (2019). Cherry, J. A. et al. Investigation into the effect of process parameters on microstructural and physical properties of 316L stainless steel parts by selective laser melting. Int. J. Adv. Manuf. Technol. 76, 869–879 (2015). Zhang, M. et al. Fatigue and fracture behaviour of laser powder bed fusion stainless steel 316L: Influence of processing parameters. Mater. Sci. Eng. A 703, 251–261 (2017). Nippes, E. F. & Ball, D. J. Copper-Contamination Cracking: Cracking Mechanism and Crack Inhibitors. Rao, S. & Al-Kawaie, A. Y. Copper Contamination Cracking in Austenitic Stainless Steel Welds. Andreau, O. Influence of the position and size of various deterministic defects on the high cycle fatigue resistance of a 316L steel manufactured by laser powder bed fusion. Int. J. Fatigue (2021). du Plessis, A. & Beretta, S. Killer notches: The effect of as-built surface roughness on fatigue failure in AlSi10Mg produced by laser powder bed fusion. Addit. Manuf. 35, 101424 (2020). Snow, Z. et al. Analysis of factors affecting fatigue performance of HIP’d laser-based powder bed fusion Ti–6Al–4V coupons. Mater. Sci. Eng. A 864, (2023). He, C., Ramani, K. & Okwudire, C. An intelligent Scanning Strategy (SmartScan) for Improved Part Quality in Multi-Laser PBD Additive Manufacturing. Addit. Manuf. (2022). Additional Declarations No competing interests reported. Supplementary Files SupplementalDocument.docx Cite Share Download PDF Status: Posted Version 1 posted 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-4301742","acceptedTermsAndConditions":true,"allowDirectSubmit":true,"archivedVersions":[],"articleType":"Article","associatedPublications":[],"authors":[{"id":295504922,"identity":"c749a631-b293-4d6d-b2b5-5cba25f18cc6","order_by":0,"name":"Jacklyn Griffis","email":"","orcid":"","institution":"Pennsylvania State University","correspondingAuthor":false,"prefix":"","firstName":"Jacklyn","middleName":"","lastName":"Griffis","suffix":""},{"id":295504923,"identity":"403b19d4-4053-4e0b-8223-331ec182af05","order_by":1,"name":"Kazi Shahed","email":"","orcid":"","institution":"Pennsylvania State University","correspondingAuthor":false,"prefix":"","firstName":"Kazi","middleName":"","lastName":"Shahed","suffix":""},{"id":295504924,"identity":"0b39a82d-b62f-4816-8595-0ed3288e8646","order_by":2,"name":"Kenneth Meinert","email":"","orcid":"","institution":"Applied Research Laboratory at Pennsylvania State University","correspondingAuthor":false,"prefix":"","firstName":"Kenneth","middleName":"","lastName":"Meinert","suffix":""},{"id":295504925,"identity":"6a48f924-007d-4b2f-830f-443edf56374a","order_by":3,"name":"Buket Yilmaz","email":"","orcid":"","institution":"Pennsylvania State University","correspondingAuthor":false,"prefix":"","firstName":"Buket","middleName":"","lastName":"Yilmaz","suffix":""},{"id":295504926,"identity":"107a18db-7c56-45dc-b31e-6de5fd663d42","order_by":4,"name":"Matthew Lear","email":"","orcid":"","institution":"Applied Research Laboratory at Pennsylvania State University","correspondingAuthor":false,"prefix":"","firstName":"Matthew","middleName":"","lastName":"Lear","suffix":""},{"id":295504927,"identity":"5f2cb87a-2939-41c7-806d-b93dbf4fab2b","order_by":5,"name":"Guha Manogharan","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAAArElEQVRIiWNgGAWjYHAC9o8fKiAsCWK1sDFLnCFVCwNvGyla5COy0x5Izrtjb3CA+eBtHmK0GN7I3W5QuO1Z4oYDbMnWxGmZkbtBQnLb4QSDAzxm0sRr4Z1zGOgw/m/EaZGXyN0mwdtwmHHDAR424rQY8LzdbCxx7FnizMNsxpZziLKlPXfjww81d+z5jjc/vPGGKFsOgCkgyUyMcrAtDTAto2AUjIJRMApwAQAVXDQCUJomWwAAAABJRU5ErkJggg==","orcid":"","institution":"Pennsylvania State University","correspondingAuthor":true,"prefix":"","firstName":"Guha","middleName":"","lastName":"Manogharan","suffix":""}],"badges":[],"createdAt":"2024-04-21 17:54:02","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-4301742/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-4301742/v1","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":55508143,"identity":"b725f9ee-c831-4961-ace7-1e0d96291d9d","added_by":"auto","created_at":"2024-04-29 12:12:06","extension":"jpg","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":125229,"visible":true,"origin":"","legend":"\u003cp\u003e\u003cem\u003eA schematic representation of Multi-Material Laser Powder Fusion (MM-LPBF) through Selective Powder Deposition (SPD) which provides an opportunity to re-imagine what is possible via metal AM.\u003c/em\u003e\u003c/p\u003e","description":"","filename":"1.jpg","url":"https://assets-eu.researchsquare.com/files/rs-4301742/v1/0137e9083bdc1a49c1be37cc.jpg"},{"id":55508141,"identity":"3ea7b64b-e4cb-4c0b-bc42-ad49359d5b91","added_by":"auto","created_at":"2024-04-29 12:12:06","extension":"jpg","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":196226,"visible":true,"origin":"","legend":"\u003cp\u003e\u003cem\u003eEBSD scans of four orientation witness coupons of steel (top), fusion plane (middle), and bronze (bottom) portion.\u003c/em\u003e\u003c/p\u003e","description":"","filename":"2.jpg","url":"https://assets-eu.researchsquare.com/files/rs-4301742/v1/ca691c50b74d295773522ae7.jpg"},{"id":55509080,"identity":"cddc5ee1-b517-401e-8e35-e8384a790530","added_by":"auto","created_at":"2024-04-29 12:20:06","extension":"jpg","order_by":3,"title":"Figure 3","display":"","copyAsset":false,"role":"figure","size":193064,"visible":true,"origin":"","legend":"\u003cp\u003e\u003cem\u003eEDS Map scans of the fusion plane of four oriental witness coupons showing iron (blue) and copper (orange) distributions. Optical microscopy of defects found near the interface. Black box in (SS, Br)z denotes the melt pool region presented in Figure 6.\u003c/em\u003e\u003c/p\u003e","description":"","filename":"3.jpg","url":"https://assets-eu.researchsquare.com/files/rs-4301742/v1/5960e906c5d22f1459243dfa.jpg"},{"id":55509079,"identity":"f54cffc1-14fa-4138-91df-2e7157c2aff3","added_by":"auto","created_at":"2024-04-29 12:20:06","extension":"jpg","order_by":4,"title":"Figure 4","display":"","copyAsset":false,"role":"figure","size":100011,"visible":true,"origin":"","legend":"\u003cp\u003e\u003cem\u003eIntermittent micro-CT showing the propagation of internal as-built cracking towards failure. The left half of the specimens were scanned to maintain finer (25 μm) resolution. Black circles show the pin contact of the loading cylinders.\u003c/em\u003e\u003c/p\u003e","description":"","filename":"4.jpg","url":"https://assets-eu.researchsquare.com/files/rs-4301742/v1/8d1089aefb9f2c54531faf44.jpg"},{"id":55508145,"identity":"8f8fb2af-76a3-4c80-8272-2fe3dd25e5e6","added_by":"auto","created_at":"2024-04-29 12:12:06","extension":"jpg","order_by":5,"title":"Figure 5","display":"","copyAsset":false,"role":"figure","size":149297,"visible":true,"origin":"","legend":"\u003cp\u003e\u003cem\u003eComparative study between simulated strain (\u003c/em\u003eϵ\u003csub\u003eyy\u003c/sub\u003e\u003cem\u003e achieved through FEA and experimental strain (\u003c/em\u003eϵ\u003csub\u003eyy\u003c/sub\u003e\u003cem\u003e achieved through DIC. Load-Displacement relation for simulated and experimental crosshead behavior is presented. Simulated Von Mises stress distribution for three displacement increments is included.\u003c/em\u003e\u003c/p\u003e","description":"","filename":"5.jpg","url":"https://assets-eu.researchsquare.com/files/rs-4301742/v1/21eb502061cab3599fa0ad17.jpg"},{"id":55508142,"identity":"a006ce44-6563-4abc-996c-24648382c5b0","added_by":"auto","created_at":"2024-04-29 12:12:06","extension":"jpg","order_by":6,"title":"Figure 6","display":"","copyAsset":false,"role":"figure","size":92714,"visible":true,"origin":"","legend":"\u003cp\u003e\u003cem\u003eMechanisms of melt pool formation. Right image shows optical microscopy of solidified (SS, Br)z interfacial zone taken from black-boxed region in Figure 3.\u003c/em\u003e\u003c/p\u003e","description":"","filename":"6.jpg","url":"https://assets-eu.researchsquare.com/files/rs-4301742/v1/1306dbd56150876a68bd6446.jpg"},{"id":55508147,"identity":"7d391d68-b943-43cc-b317-8c352afdc52b","added_by":"auto","created_at":"2024-04-29 12:12:06","extension":"jpg","order_by":7,"title":"Figure 7","display":"","copyAsset":false,"role":"figure","size":197610,"visible":true,"origin":"","legend":"\u003cp\u003e\u003cem\u003eDirection of crack propagation the multi-material gyroid specimen during three-point bending flexural testing. Vertical red dotted lines follow the interfaces of the labeled materials. Blue and orange boxes show progressive interfaces which result in failure by mode of interfacial delamination.\u003c/em\u003e\u003c/p\u003e","description":"","filename":"7.jpg","url":"https://assets-eu.researchsquare.com/files/rs-4301742/v1/c4285efaed3efa4296e3d313.jpg"},{"id":58054230,"identity":"e9eeab28-76ed-4c71-95f7-5138bd110cf2","added_by":"auto","created_at":"2024-06-10 13:44:42","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":1482030,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-4301742/v1/17cc7f81-5fcc-46d6-bca5-e260f6362cdc.pdf"},{"id":55508146,"identity":"fb0d397e-e0d0-4d13-ae05-a852fc977926","added_by":"auto","created_at":"2024-04-29 12:12:06","extension":"docx","order_by":2,"title":"","display":"","copyAsset":false,"role":"supplement","size":1593860,"visible":true,"origin":"","legend":"","description":"","filename":"SupplementalDocument.docx","url":"https://assets-eu.researchsquare.com/files/rs-4301742/v1/42bf699e8e2438aa06016cae.docx"}],"financialInterests":"No competing interests reported.","formattedTitle":"Re-Imagining Additive Manufacturing through Multi-Material Laser Powder Bed Fusion","fulltext":[{"header":"1.\tINTRODUCTION","content":"\u003cp\u003eMulti-material laser powder bed fusion (MM-LPBF) is an evolving advanced manufacturing capability for spatially graded architectures, enabling the variation of mechanical, thermal, and other properties based on functional requirements\u003csup\u003e1\u003c/sup\u003e. As shown in Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003e, selective powder deposition (SPD) recoating provides reliable means of depositing multiple materials based on 3D computer aided design (CAD) model (up to three powders) within controlled regional portions of the build plate\u003csup\u003e2\u003c/sup\u003e. Each material region is selectively fused with laser processing conditions that are tailored to each material on a layer-by-layer basis. Recent advancements in multi-material additive manufacturing techniques have significantly addressed the previous monolithic design challenge in L-PBF by enabling spatially tailored parts for functional requirements\u003csup\u003e3\u003c/sup\u003e. Although such approaches have gained significant attention in manufacturing research, they have been largely hindered by the ability to truly achieve concurrent design and manufacturing of multi-material AM as shown in Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003e. Both the engineering and scientific community has always been intrigued by the self-evident observations in various biological systems and manufacturing-dependent industries, ranging from nanometer-scale applications like solar energy cell sheet layering\u003csup\u003e4\u003c/sup\u003e to MM metal-composite aviation engine blades\u003csup\u003e5\u003c/sup\u003e. For instance, multiple natural occurrences leverage a difference in stiffness between materials to provide a structural core or protective shell, paired with a flexible, non-load bearing material for secondary supporting function\u003csup\u003e6,7\u003c/sup\u003e.\u003c/p\u003e \u003cp\u003eThe ability to concurrently design and manufacture highly complex multi-material structures is of high interest for a wide range of applications such as: high temperature surface fluidic structures\u003csup\u003e8\u003c/sup\u003e, solid state energy devices\u003csup\u003e9,10\u003c/sup\u003e, biomedical AM implants with functional surfaces\u003csup\u003e11\u003c/sup\u003e, and corrosion resistant graded components\u003csup\u003e12\u003c/sup\u003e. In order to demonstrate the unique capability to simultaneously design and manufacture highly complex structures in multi-material within a single 3D geomoetry, this study leverages triply periodic minimal surfaces (TPMS), which are characterized by a smooth continuous surface, interconnected porosity, and zero mean curvature\u003csup\u003e13\u003c/sup\u003e. TPMS structures offer similar mechanical properties to solid traditionally manufactured parts with reduced weight and material consumption\u003csup\u003e14\u003c/sup\u003e. Among various TPMS topological classes, the sheet-based gyroid structure has shown promise for biomedical applications due to its high surface area-to-volume ratio and tortuosity, which enhances bone-to-implant contact area and bone ingrowth and limit stress-shearing that arises due to the large stiffness difference between traditional implants and human bone\u003csup\u003e15\u003c/sup\u003e. TPMS structures have also found applications in tissue engineering\u003csup\u003e16\u0026ndash;19\u003c/sup\u003e, construction\u003csup\u003e20,21\u003c/sup\u003e, electrical\u003csup\u003e22\u003c/sup\u003e, acoustic\u003csup\u003e23\u003c/sup\u003e, transportation\u003csup\u003e24\u003c/sup\u003e, chemical\u003csup\u003e25\u003c/sup\u003e, optical\u003csup\u003e26\u003c/sup\u003e, and energy\u003csup\u003e27,28\u003c/sup\u003e industries. The unique design features of TPMS, including pore size control\u003csup\u003e29,30\u003c/sup\u003e, functional grading capability\u003csup\u003e31,32\u003c/sup\u003e, high surface area-to-volume ratio\u003csup\u003e33\u003c/sup\u003e, high strength combined with low stiffness\u003csup\u003e34\u003c/sup\u003e, and favorable fluid dynamic characteristics\u003csup\u003e35\u003c/sup\u003e, have attracted significant interest in recent years.\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003eRecent efforts in metal-based AM processes that are capable of multi-material functional gradation include directed energy deposition (DED), which has poor part feature resolution and surface finish and require substantial post-AM re-surfacing and post-processing, such as machining \u003csup\u003e36\u003c/sup\u003e. This makes manufacturing of complex geometries such as TPMS structures difficult, if not impossible. Other state-of-the-art AM processing such as Wire Arc Additive Manufacturing (WAAM) cannot achieve both complex design and multi-material capabilities\u003csup\u003e37\u003c/sup\u003e. The emergence of MM-LPBF capabilities presented in this work allows for a new range of precision in advanced manufacturing of complex structures (e.g., TPMS) with high-precision volumetric selective placement of multi-materials which could also help address the application-driven latency into industries requiring multi-functional AM capabilities at higher resolution than existing methods via DED techniques.\u003c/p\u003e \u003cp\u003eWhile the motivation for multi-material AM processing is well documented\u003csup\u003e8,38,39\u003c/sup\u003e, there is a lack of understanding into the effects of processing conditions on resulting material characteristics (e.g., melt pool morphology, microstructure morphology, and AM-process induced defects), and the resulting mechanical response (e.g., strength and fracture mechanisms) in MM-LPBF. Prior studies have predominantly focused on single alloy in L-PBF and have not fully leveraged the new geometrical freedom and resolution offered by selective powder deposition in LPBF systems beyond manual switching over of secondary metal to print bimetallic bulk specimens\u003csup\u003e40\u0026ndash;43\u003c/sup\u003e. In summary, the motivation for this research lies in the critical need to better understand the processing science of MM-LPBF to avoid prevailing AM processing defects, such as porosity, cracking, and material cross-contamination to accelerate advancements and adoption of MM-LPBF manufacturing technique\u003csup\u003e39,44\u003c/sup\u003e.\u003c/p\u003e \u003cp\u003eTo the best of author\u0026rsquo;s knowledge, this is the first study focused on understanding the manufacturing and resulting performance of multi-material TPMS that can now be realized through MM-LPBF. Based on previous work in multi-material AM through DED, it is hypothesized that failure will originate and propagate through the material with the lowest yield strength. The origin and propagation of failure of a sheet-based gyroid specimen manufactured of 904L stainless steel and bronze (CuSn10) via MM-LPBF under three-point flexural testing is examined. As detailed in the Materials and Methods Supplementary document, this study also presents a comprehensive analysis on fracture behavior, and constituent material compatibility across the fusion zone in MM-LPBF by employing digital image correlation (DIC) coupled with finite element analysis (FEA), electron backscatter dispersion spectroscopy (EBSD), and microcomputed tomography (MCT) to understand the effects of as-built defects on mechanical performance in MM-LPBF manufacturing. Additional analysis of as-built cracking and porosity defects and fusion zone microstructure imply a joint contribution of thermomechanical material disparity and material incompatibility at the given machine parameters.\u003c/p\u003e"},{"header":"2.\tRESULTS","content":"\u003cdiv id=\"Sec3\" class=\"Section2\"\u003e \u003ch2\u003e2.1. Microstructural Characterization\u003c/h2\u003e \u003cp\u003eWitness coupons of four material orientations were fabricated through MM-LPBF (Fig.\u0026nbsp;\u003cspan refid=\"Fig3\" class=\"InternalRef\"\u003e3\u003c/span\u003e) to understand the influence of fusion plane and material compatibility with respect to the processing conditions. As shown in Fig.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003e, AM process induced cracks that were parallel to the fusion plane was evident in all the orientations except Bronze on Stainless Steel (SS, Br)z. Results obtained from EBSD and scanning electron microscopy (SEM) analyses provide insight into the crack patterns and their underlying causes. Within the various degrees of cracking, all severe as-built defects occurred on the steel side of the fusion plane. The root of nano-scale cracking occurs at the interface between the fusion zone and the steel and extends perpendicular to the fusion plane like dendritic growth as shown in Fig.\u0026nbsp;\u003cspan refid=\"Fig3\" class=\"InternalRef\"\u003e3\u003c/span\u003e. The cause of this cracking could be attributed to a mismatch in thermophysical properties across a discrete material change while sintering. This pattern of cracking was also observed in other material orientations (Br, SS)y, (SS, Br)z, and (Br, SS)z as shown in Fig.\u0026nbsp;\u003cspan refid=\"Fig3\" class=\"InternalRef\"\u003e3\u003c/span\u003e where similar microstructure across all three scanned regions and similar process-induced defects at the fusion plane were observed. This indicates that the direction of recoating blade in selective powder deposition does not impact the resultant microstructure and defect formation at the multi-material interface. EBSD analysis of specimen (Br, SS)z reveals micro-scale cracking present strictly within the stainless-steel grain structures as shown in Fig.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003e. Grain structure at the fusion plane suggests that the higher energy density used to process SS caused unstable re-melting of the bronze, resulting in severe defects as shown in Fig.\u0026nbsp;\u003cspan refid=\"Fig3\" class=\"InternalRef\"\u003e3\u003c/span\u003e. and an elongated interface, in comparison to the other three orientations. EBSD of all four orientations show grain refinement at the fusion zone as a defining feature of the interface which clearly reflects the higher cooling rate in MM-LPBF due to the heterogenous mixing of alloying elements.\u003c/p\u003e \u003cp\u003eIt should be observed that lack of AM process induced cracks with complete fusion were observed in one orientation (SS, Br)z. Nondestructive evaluation and thermomechanical simulation of these specimens has demonstrated a preferential material orientation along the build direction (SS, Br)z when compared to (Br, SS)\u003csup\u003e2\u003c/sup\u003e. It is evident that orientation of material sections, as well as dissimilarities in thermal material properties and energy input required to reach their solidification temperature play concurrent roles in thermal build history and thus, thermally induced residual stress and crack formation. This effect needs to be further studied by including the effects of unmelted powders and sacrificial support structures in underlying layers because the thermal stress on part geometry during MM-LPBF would be impacted by the differences in thermal conductivity of the different powders in this advanced manufacturing process.\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec4\" class=\"Section2\"\u003e \u003ch2\u003e2.2. EDS Investigation for elemental diffusion and melt pool morphology\u003c/h2\u003e \u003cp\u003eEnergy dispersive spectroscopy (EDS) analysis of witness cube (Br, SS)y revealed an elongated \"blowout\" region of copper contaminates lateral to the recoating direction. This cube's fusion plane was positioned parallel to the recoating blade trajectory during the additive manufacturing process. The selective powder deposition process involves two key steps, (\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e) the powder drums which deposit a 150\u0026ndash;200 \u003cspan class=\"InlineEquation\"\u003e\u003cspan class=\"mathinline\"\u003e\\(\\mu m\\)\u003c/span\u003e\u003c/span\u003e layer of powder, according to the 2D slicing geometry, and (\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e) a suction and skiving blade which cuts that layer of powder down to a layer height appropriate for sintering (40\u0026ndash;50 \u003cspan class=\"InlineEquation\"\u003e\u003cspan class=\"mathinline\"\u003e\\(\\mu m\\)\u003c/span\u003e\u003c/span\u003e). It was presumed that the movement of the skive across the powder layer could disturb the accuracy of the selective powder deposition chamber within the XY plane. The presence of this localized copper contamination, shown in the EDS of cube (Br, SS)y, suggests the possibility that the skive blade may have played a role in spreading copper particles as it cuts across the build volume.\u003c/p\u003e \u003cp\u003eMicron-scale cracking within (Br, SS)z has allowed for unmelted bronze powder to become trapped. This cracking was observed to continue around the entire circumference and extend a few millimeters into the cube. No other specimen was observed to have cracking severe enough to trap powder. Cubes (Br, SS)y and (SS, Br)x presented similar cracking in scale, however (Br, SS)y observed a more elongated region of cracking extending from the fusion plane. This was attributed to the contamination of bronze powder into the steel region, leading to more severe copper contamination cracking. Cracking from these specimens originates at the steel-interface region and extends deeper into the steel. These dendritic cracks then connect laterally, with more nano-scale cracking observed parallel to the fusion plane. These cracks are evidence of residual process-induced stress build up. Notably, cube (SS, Br)z (bronze sintered over steel) exhibited no nano- or micron-scale cracking. EDS shows a depth of penetration sufficient to diffuse the first copper layer into the steel substrate, however a few instances of circular bronze particles at the interface suggest partial melting.\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec5\" class=\"Section2\"\u003e \u003ch2\u003e2.3. Mechanical Testing\u003c/h2\u003e \u003cdiv id=\"Sec6\" class=\"Section3\"\u003e \u003ch2\u003e2.3.1. Intermittent Micro-CT\u003c/h2\u003e \u003cp\u003eThe intermittent micro-CT process involved the repeated plastic deformation of the specimens, followed by successive micro-CT scans to capture the deformation of the gyroid\u0026rsquo;s internal structure as failure progressed. This iterative approach was performed three times to document the stages leading to failure. While the resolution of micro-CT is not sufficient to observe the nano- and micron-scale cracking shown in EBSD and EDS, the intermittent micro-CT revealed that the location of failure initiation was consistent with the location of these cracks. The ultimate mode of failure was characterized by the delamination of the two material sections. Figure\u0026nbsp;\u003cspan refid=\"Fig7\" class=\"InternalRef\"\u003e7\u003c/span\u003e shows that cracks which lead to failure propagate from the interface region, and initially extend perpendicular to the fusion zone, into the steel region. These cracks then join along the interface until delamination of the bronze and steel regions is observed.\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec7\" class=\"Section3\"\u003e \u003ch2\u003e2.3.2. Digital Image Correlation with Preliminary FEA\u003c/h2\u003e \u003cp\u003eThe presented preliminary FEA simulations enabled the comparison of experimental and simulated strain values and introduced a method to determine the stress distribution across the specimen. Figure\u0026nbsp;\u003cspan refid=\"Fig5\" class=\"InternalRef\"\u003e5\u003c/span\u003e presents a comparative analysis of the FEA and DIC results at three distinct points along the elastic deformation progression, where the final displacement of 3 mm signifies the experimental yielding point.\u003c/p\u003e \u003cp\u003eThe simulated load at the experimental yielding displacement is within 12% of the measured experimental load. FEA simulation allows the determination of the stress across the specimen, which is otherwise unachievable using experimental or analytical methods. These simulated stress values provided additional context for understanding the material response under load, particularly with respect to the onset of yielding. At the experimental yield displacement, the simulation indicates a Von Mises stress magnitude consistent with failure within bronze material sections. Additionally, the FEA indicates that the experiential beams consistently fail at a lower load than what is computationally expected. This indicates that, in combination with the intermittent micro-CT results, the as-built nano- and micron-scale cracking near the interface leads to premature failure. In this context, premature failure should be defined as yielding in a material region which is not consistent with the material of the lowest ultimate tensile strength (UTS).\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003c/div\u003e \u003c/div\u003e"},{"header":"3.\tDISCUSSION","content":"\u003cp\u003e \u003cem\u003eInterfacial Distribution of Elements and mechanisms of melt pool formation\u003c/em\u003e \u003c/p\u003e \u003cp\u003eSeveral process-driven factors influence the interfacial distribution of elements in parts manufactured using MM-LPBF. Contributing factors are critical to identify and understand to limit, or predict defect formation, and interfacial morphology. LPBF, especially compared to traditional welding processes, boasts significantly higher cooling rates (up to \u003cspan class=\"InlineEquation\"\u003e\u003cspan class=\"mathinline\"\u003e\\({10}^{7}\\frac{mm}{s},\\)\u003c/span\u003e\u003c/span\u003e compared to \u003cspan class=\"InlineEquation\"\u003e\u003cspan class=\"mathinline\"\u003e\\({10}^{3}\\frac{mm}{s}-{10}^{4}\\frac{mm}{s}\\)\u003c/span\u003e\u003c/span\u003e). Rapid cooling is exacerbated in steel regions adjacent to the interface due to the high thermal conductivity of copper alloys. Higher cooling rates in metals are known to microstructural grain refinement\u003csup\u003e45\u0026ndash;47\u003c/sup\u003e. The effects of rapid solidification are clear in the EBSD scan across all four-witness cube\u0026rsquo;s fusion zones shown in Fig.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003e. The EBSD shows that the interfacial grain structure is significantly smaller than that of either constituent material. These ultrafine grains are characteristic of rapid cooling during the LPBF process\u003csup\u003e47,48\u003c/sup\u003e.\u003c/p\u003e \u003cp\u003eThe \u0026lsquo;dilution effect,\u0026rsquo; analogous to that observed in cladding operations\u003csup\u003e49\u0026ndash;51\u003c/sup\u003e, is clearly observed both in the EDS of Fe-Cu distribution across the interface, and in the optical image (Fig.\u0026nbsp;\u003cspan refid=\"Fig3\" class=\"InternalRef\"\u003e3\u003c/span\u003e). This analogy is only relevant for the two witness coupons ((SS, Br)z, and Br, SS)z) in which the interfacial plane is parallel to the build plate. As multiple layers of a secondary material are deposited over a substrate of a primary material, the utmost layer of the primary material remelts into the newest layer as the secondary material is sintered on top. This region forms the visual \u0026lsquo;interface,\u0026rsquo; which is characterized by a higher chemical composition of elements from both alloys, and a clear region of grain refinement. With subsequent layers, the distribution of the primary material becomes negligible.\u003c/p\u003e \u003cp\u003eThe mechanism driving the diffusion of elements includes a highly turbulent melt pool and conductive forces within the melt pool. Marangoni convection in the melt pool is the main active force describing the melting of powder and the mass/heat transfer throughout the pool\u003csup\u003e52\u003c/sup\u003e. Marangoni convection causes the circular swirling of both molten metals within the melt pool. This is visually evident post-solidification in Fig.\u0026nbsp;\u003cspan refid=\"Fig6\" class=\"InternalRef\"\u003e6\u003c/span\u003e. This, in combination with gravitational forces acting on materials of varying density and material-wise energy density differences lead to a heterogeneous material distribution throughout the interface. Regions of Fe-rich and Cu-rich regions are present for all four material orientations and are denoted in Fig.\u0026nbsp;\u003cspan refid=\"Fig3\" class=\"InternalRef\"\u003e3\u003c/span\u003e.\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003eAs-build cracking near the interface was observed to be dependent on material orientation. Identified contributing factors are three-fold: (\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e) The physical mismatch in thermal material properties between materials leads to inconsistent thermal expansion and contraction under the same thermal loads. (\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e) While printing steel over bronze, the expected energy absorption from the bronze substrate is much higher than what is expected for fusing steel over a steel substrate due to the high thermal conductivity of copper alloys. This condition is akin to processing steel at a lower energy density than is recommended by most manufactures. Defects associated with the low energy density processing of steel include major and minor porosity and micro-cracking\u003csup\u003e53\u0026ndash;55\u003c/sup\u003e, both of which are present in the optical images of Fig.\u0026nbsp;\u003cspan refid=\"Fig3\" class=\"InternalRef\"\u003e3\u003c/span\u003e. (\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e) Copper contamination within austenitic steel weldments can lead to the formation of cracking between steel grain boundaries. Copper contamination cracking (CCC)\u003csup\u003e56,57\u003c/sup\u003e occurs as copper is introduced to the heat-affected zone and leads to the diffusion of copper along/between the steel grain boundaries during solidification. This is consistent with the EDS results in Fig.\u0026nbsp;\u003cspan refid=\"Fig3\" class=\"InternalRef\"\u003e3\u003c/span\u003e, showing the copper contamination within into the steel cracks, approximately 150 \u003cspan class=\"InlineEquation\"\u003e\u003cspan class=\"mathinline\"\u003e\\(\\mu m\\)\u003c/span\u003e\u003c/span\u003e away from the interface.\u003c/p\u003e \u003cdiv id=\"Sec9\" class=\"Section2\"\u003e \u003ch2\u003e3.1. Mechanical Testing\u003c/h2\u003e \u003cp\u003eIntermittent micro-CT was performed in the investigation into the failure mechanisms and material behavior for multi-material TPMS components. This method provides insights into the origin and progression of failure, and when coupled with DIC, the distribution of strains, and the identification of key factors influencing structural integrity. Figure\u0026nbsp;\u003cspan refid=\"Fig7\" class=\"InternalRef\"\u003e7\u003c/span\u003e shows that cracks which lead to failure originate from the regions which contain nano- and micron-scale cracking (Fig.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003e, \u003cspan refid=\"Fig3\" class=\"InternalRef\"\u003e3\u003c/span\u003e). Visual inspection of the fractured regions showed steel on both opened sides of the cracks, substantiating the fact that failure occurred solely within the steel portion because of as-build defects and cracking. The origin of crack propagation is consistent with the location of the micro- and nano-scale cracking in Fig.\u0026nbsp;\u003cspan refid=\"Fig3\" class=\"InternalRef\"\u003e3\u003c/span\u003e. Provided mechanical failure has been shown to have occurred prematurely according to FEA simulation, it is theorized that these sub-scale cracks were the cause for failure. Superficial defects in AM have been shown to have massive adverse effects on cyclical loading in fatigue failure, especially compared to static loading\u003csup\u003e58\u0026ndash;60\u003c/sup\u003e. These findings emphasize the importance of as-built defect mitigation in multi-material LPBF processes, as these defects can serve as critical stress concentration points leading to premature structural failure.\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cdiv id=\"Sec10\" class=\"Section3\"\u003e \u003ch2\u003e3.1.1. Digital Image Correlation with Preliminary FEA\u003c/h2\u003e \u003cp\u003eThe strain maps obtained from both FEA and DIC exhibit fair agreement concerning the distribution of strain across the MSMG specimen. This initial agreement between the FEA and DIC suggests that finite element simulation is effective in capturing preliminary deformation characteristics. Notwithstanding the overall agreement, there are targeted areas where the DIC strain maps show elevated positive strain. These disparities can be attributed to premature failure events. The regions are solely located within the steel section adjacent to the fusion zone. Premature failure indicates that factors other than material strength played a dominant role in the failure mechanism such as thermomechanically induced defects or poor alloying combinations. These findings align with the physical manifestation of as-built cracking in the same vicinity.\u003c/p\u003e \u003cp\u003eDespite the areas of discrepancy mentioned above, the agreement between the preliminary FEA and DIC strain maps underscores the capability of FEA to effectively simulate multi-material LPBF complex structures. However, it is crucial to complement FEA with experimental techniques like DIC to validate and verify simulation results, particularly in cases where localized material behavior and premature failures are of concern. Continued efforts towards calibrating and verifying this FEA model will be used to inform future design work using MM-LPBF of complex geometries.\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv id=\"Sec11\" class=\"Section2\"\u003e \u003ch2\u003e3.2. Mitigating Thermomechanical Induced Defects\u003c/h2\u003e \u003cp\u003eAs apparent in EBSD images at the fusion zone (Fig.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003e) and as indicated by the premature failure in mechanical testing (Fig.\u0026nbsp;\u003cspan refid=\"Fig7\" class=\"InternalRef\"\u003e7\u003c/span\u003e), as-build defects seen at the fusion plane are severe and detrimental to mechanical strength. Previous work has indicated thermally induced strains concentrated at the fusion plane due to a dissimilarity in thermal expansion and conduction\u003csup\u003e2\u003c/sup\u003e. Future research efforts should focus on reducing thermal gradients at the fusion plane to eliminate thermal strain concentration. A combination of applied controls theory for novel laser scanning strategy and in-situ process monitoring should aim towards maintaining uniform thermal expansion across the fusion plane\u003csup\u003e61\u003c/sup\u003e. Leveraging multi-laser LPBF systems may provide additional flexibility in scanning strategy design and thermal history control. Further investigation into other compatible metallic powder bed systems (e.g., electron beam melting (EBM)) is warranted to expand the MMAM application of SPD.\u003c/p\u003e \u003c/div\u003e"},{"header":"4.\tCONCLUSION","content":"\u003cp\u003eThe advent of multi-material metal fabrication through LPBF has opened a new advanced manufacturing with concurrent design freedom of structural design, local material assignment which could allow engineers and designers to push boundaries on modern manufacturing. This study has demonstrated the while MM-LPBF enables the creation of complex, multifunctional components the state-of-art knowledge in single material LPBF needs to be reimagined to account for interaction across multiple length scales.\u003c/p\u003e \u003cp\u003e1. Defects observed at the interface of parts fabricated through MM-LPBF are shown to be highly dependent on material orientation with respect to the build direction.\u003c/p\u003e \u003cp\u003e2. Cracking and defects, which occur solely between the interfacial region and 904L SS, are attributed to a mismatch in thermophysical properties, differences in volumetric energy density (VED) for alloy-specific processing condition, and copper contamination cracking.\u003c/p\u003e \u003cp\u003e3. Rapid solidification, Marangoni convection and the \u0026lsquo;dilution\u0026rsquo; effect are the main mechanisms behind elemental diffusion within the interface.\u003c/p\u003e \u003cp\u003e4. The melting of a material processed with a high VED over a material processed with a low VED leads to hydrodynamic instability in the melt pool, and an elongated interface.\u003c/p\u003e \u003cp\u003e5. The mechanical testing of complex structures reveals premature failure which originates from nano- and micron-scale cracking near the interface, when compared to FEA simulation.\u003c/p\u003e \u003cp\u003eThe utilization of thermomechanical simulation and in-situ process monitoring emerges as essential Integrated Computational Materials Engineering (ICME) tools to provide predictive insights into thermal build-up for optimized parameter selection in MM-LPBF. In addition, design methods of MM-LPBF structures and build preparation (e.g., build orientation, leveraging multi-material for dissolvable supports and/or This study not only highlights existing challenges in MM-LPBF but also lays the groundwork for generating in-situ data-driven modeling methods for advanced predictive parameter selection. In addition, design methods of MM-LPBF structures and build preparation (e.g., build orientation, multi-material for dissolvable supports and/or directional heat transfer), and leveraging in-situ processing monitoring to understand melt pool dynamics will be required in future studies. In summary, this study not only highlights existing challenges in MM-LPBF but also lays the groundwork for generating in-situ data-driven modeling methods for advancing materials processing map predictive parameter selection.\u003c/p\u003e"},{"header":"Declarations","content":"\u003cp\u003e\u003cstrong\u003eData Availability\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe data supporting this study\u0026apos;s findings are available from the corresponding author upon reasonable request.\u003c/p\u003e\n\u003ch2\u003eAuthor Contribution\u003c/h2\u003e\u003cp\u003eJ.G. is credited with concept generation, data analysis and leading the manuscript preparation with contributions from all authors. K.S. and K.M. performed micro-CT numerical analysis and optical characterization. B.Y. helped with the original draft. M.L. supervised and advised on FEA simulation. G.M. contributed towards concept generation, funding, editing and overall supervision.\u003c/p\u003e\u003ch2\u003eAcknowledgement\u003c/h2\u003e\u003cp\u003eThe authors acknowledge the Applied Research Laboratory at Pennsylvania State University for their support and contributions through the Walker Graduate Assistantship.\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\u003cli\u003e\u003cspan\u003eZheng, Y., Zhang, W., Lopez, D. M. B. \u0026amp; Ahmad, R. Scientometric analysis and systematic review of multi-material additive manufacturing of polymers. Polymers 13, (2021).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eGriffis, J. C., Shahed, K. S., Okwudire, C. E. \u0026amp; Manogharan, G. P. PROCESS MODELING OF MULTI-MATERIAL LASER POWDER BED FUSION. in \u003cem\u003eSolid Freeform Fabrication 2023\u003c/em\u003e (2023).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eBandyopadhyay, A. \u0026amp; Heer, B. Additive manufacturing of multi-material structures. Mater. Sci. Eng. R Rep. 129, 1\u0026ndash;16 (2018).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eDas, S. Using Nanotechnology to Make Solar Cells Cheaper and More Efficient. AZO Cleantech (2019).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eGardiner, G. Developing next-gen, smart engine composite fan blades. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://www.compositesworld.com/news/developing-next-gen-smart-engine-composite-fan-blades\u003c/span\u003e\u003cspan address=\"https://www.compositesworld.com/news/developing-next-gen-smart-engine-composite-fan-blades\" targettype=\"URL\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e (2024).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eBiałkowski, J. \u003cem\u003eet al.\u003c/em\u003e Evolution, types, and distribution of flight control devices on wings and elytra in bark beetles. Sci. Rep. 14, 6999 (2024).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eStelzner, J., Million, S., Stelzner, I., Nelle, O. \u0026amp; Banck-Burgess, J. Micro-computed tomography for the identification and characterization of archaeological lime bark. Sci. Rep. 13, 6458 (2023).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eBinder, M. \u003cem\u003eet al.\u003c/em\u003e Potentials and Challenges of Multi-Material Processing by Laser-Based Powder Bed Fusion. (2018) doi:\u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.26153/TSW/17025\u003c/span\u003e\u003cspan address=\"10.26153/TSW/17025\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eTian, X. \u0026amp; Zhou, K. Additive Manufacturing of Energy Storage Devices. in \u003cem\u003eAdditive Manufacturing: Materials, Functionalities and Applications\u003c/em\u003e (ed. Zhou, K.) 51\u0026ndash;83 (Springer International Publishing, Cham, 2023). doi:\u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1007/978-3-031-04721-3_2\u003c/span\u003e\u003cspan address=\"10.1007/978-3-031-04721-3_2\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eCheng, M. \u0026amp; Jiang, Y. 3D-printed solid-state electrolytes for electrochemical energy storage devices. J. Mater. Res. 36, 4547\u0026ndash;4564 (2021).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eBartolomeu, F., Costa, M. M., Alves, N., Miranda, G. \u0026amp; Silva, F. S. Additive manufacturing of NiTi-Ti6Al4V multi-material cellular structures targeting orthopedic implants. Opt. Lasers Eng. 134, 106208 (2020).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eP\u0026uuml;tz, R. D. \u003cem\u003eet al.\u003c/em\u003e Microstructure and Corrosion Behavior of Functionally Graded Wire Arc Additive Manufactured Steel Combinations. Steel Res. Int. 92, 2100387 (2021).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eFeng, J., Fu, J., Yao, X. \u0026amp; He, Y. Triply periodic minimal surface (TPMS) porous structures: from multi-scale design, precise additive manufacturing to multidisciplinary applications. Int. J. Extreme Manuf. 4, 022001 (2022).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eQu, S. \u003cem\u003eet al.\u003c/em\u003e High-precision laser powder bed fusion processing of pure copper. Addit. Manuf. 48, 102417 (2021).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eTilton, M., Borjali, A., Isaacson, A., Varadarajan, K. M. \u0026amp; Manogharan, G. P. On structure and mechanics of biomimetic meta-biomaterials fabricated via metal additive manufacturing. Mater. Des. 201, 109498 (2021).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eYoo, D. J. Computer-aided porous scaffold design for tissue engineering using triply periodic minimal surfaces. Int. J. Precis. Eng. Manuf. 12, (2011).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eZhang, X. Y., Fang, G., Xing, L. L., Liu, W. \u0026amp; Zhou, J. Effect of porosity variation strategy on the performance of functionally graded Ti-6Al-4V scaffolds for bone tissue engineering. Mater. Des. 157, (2018).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eZhianmanesh, M., Varmazyar, M. \u0026amp; Montazerian, H. Fluid Permeability of Graded Porosity Scaffolds Architectured with Minimal Surfaces. ACS Biomater. Sci. Eng. 5, 1228\u0026ndash;1237 (2019).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eLi, L. \u003cem\u003eet al.\u003c/em\u003e Early osteointegration evaluation of porous Ti6Al4V scaffolds designed based on triply periodic minimal surface models. J. Orthop. Transl. 19, 94\u0026ndash;105 (2019).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eAl-Ketan, O., Rowshan, R. \u0026amp; Abu Al-Rub, R. K. Topology-mechanical property relationship of 3D printed strut, skeletal, and sheet based periodic metallic cellular materials. Addit. Manuf. 19, (2018).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eYan, C. \u003cem\u003eet al.\u003c/em\u003e Evaluation of light-weight AlSi10Mg periodic cellular lattice structures fabricated via direct metal laser sintering. J. Mater. Process. Technol. 214, 856\u0026ndash;864 (2014).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eTorquato, S. \u0026amp; Donev, A. Minimal surfaces and multifunctionality. \u003cem\u003eProc. R. Soc. Math. Phys. Eng. Sci.\u003c/em\u003e 460, 1849\u0026ndash;1856 (2004).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eAbueidda, D. W., Jasiuk, I. \u0026amp; Sobh, N. A. Acoustic band gaps and elastic stiffness of PMMA cellular solids based on triply periodic minimal surfaces. Mater. Des. 145, (2018).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eLiverani, E., Lutey, A. H. A., Fortunato, A. \u0026amp; Ascari, A. Characterization of lattice structures for additive manufacturing of lightweight mechanical components. \u003cem\u003eASME 2017 12th Int. Manuf. Sci. Eng. Conf. MSEC 2017 Collocated JSMEASME 2017 6th Int. Conf. Mater. Process.\u003c/em\u003e 2, 1\u0026ndash;8 (2017).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eThomas, N. \u003cem\u003eet al.\u003c/em\u003e 3D printed spacers based on TPMS architectures for scaling control in membrane distillation. J. Membr. Sci. 581, (2019).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eTurner, M. D. \u003cem\u003eet al.\u003c/em\u003e Miniature chiral beamsplitter based on gyroid photonic crystals. Nat. Photonics 7, (2013).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003ePeng, H., Gao, F. \u0026amp; Hu, W. Design, modeling and characterization of triply periodic minimal surface heat exchangers with additive manufacturing. in \u003cem\u003eSolid Freeform Fabrication\u003c/em\u003e 2019: \u003cem\u003eProceedings of the 30th Annual International Solid Freeform Fabrication Symposium - An Additive Manufacturing Conference, SFF 2019\u003c/em\u003e (2019).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eKim, J. \u0026amp; Yoo, D. J. 3D printed compact heat exchangers with mathematically defined core structures. J. Comput. Des. Eng. 7, (2020).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eVijayavenkataraman, S., Zhang, L., Zhang, S., Fuh, J. Y. H. \u0026amp; Lu, W. F. Triply periodic minimal surfaces sheet scaffolds for tissue engineering applications: An optimization approach toward biomimetic scaffold design. ACS Appl. Bio Mater. 1, 259\u0026ndash;269 (2018).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eWalker, J. M. \u003cem\u003eet al.\u003c/em\u003e Design and mechanical characterization of solid and highly porous 3D printed poly(propylene fumarate) scaffolds. Prog. Addit. Manuf. 2, (2017).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eM. Afshar, A. Pourkamali Anaraki, H. Montazerian, J. K. Additive manufacturing and mechanical characterization of graded porosity scaffolds designed based on triply periodic minimal surface architectures. J. Mech. Behav. Biomed. Mater. (2016).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eAfshar, M., Pourkamali Anaraki, A. \u0026amp; Montazerian, H. Compressive characteristics of radially graded porosity scaffolds architectured with minimal surfaces. Mater. Sci. Eng. C 92, 254\u0026ndash;267 (2018).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eYang, S. D., Lee, H. G. \u0026amp; Kim, J. A phase-field approach for minimizing the area of triply periodic surfaces with volume constraint. Comput. Phys. Commun. 181, (2010).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eKapfer, S. C., Hyde, S. T., Mecke, K., Arns, C. H. \u0026amp; Schr\u0026ouml;der-Turk, G. E. Minimal surface scaffold designs for tissue engineering. Biomaterials 32, 6875\u0026ndash;6882 (2011).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eCastro, A. P. G., Pires, T., Santos, J. E., Gouveia, B. P. \u0026amp; Fernandes, P. R. Permeability versus design in TPMS scaffolds. Materials 12, (2019).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eGhanavati, R., Naffakh-Moosavy, H., Moradi, M. \u0026amp; Eshraghi, M. Printability and microstructure of directed energy deposited SS316l-IN718 multi-material: numerical modeling and experimental analysis. Sci. Rep. 12, 1\u0026ndash;16 (2022).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eHauser, T. \u003cem\u003eet al.\u003c/em\u003e Multi-Material Wire Arc Additive Manufacturing of low and high alloyed aluminium alloys with in-situ material analysis. J. Manuf. Process. 69, 378\u0026ndash;390 (2021).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eWei, C. \u0026amp; Li, L. Recent progress and scientific challenges in multi-material additive manufacturing via laser-based powder bed fusion. Virtual Phys. Prototyp. 16, 347\u0026ndash;371 (2021).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eNazir, A. \u003cem\u003eet al.\u003c/em\u003e Multi-material additive manufacturing: A systematic review of design, properties, applications, challenges, and 3D printing of materials and cellular metamaterials. Mater. Des. 226, 111661 (2023).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eLiu, Z. H., Zhang, D. Q., Sing, S. L., Chua, C. K. \u0026amp; Loh, L. E. Interfacial characterization of SLM parts in multi-material processing: Metallurgical diffusion between 316L stainless steel and C18400 copper alloy. Mater. Charact. 94, 116\u0026ndash;125 (2014).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eSing, S. L., Lam, L. P., Zhang, D. Q., Liu, Z. H. \u0026amp; Chua, C. K. Interfacial characterization of SLM parts in multi-material processing: Intermetallic phase formation between AlSi10Mg and C18400 copper alloy. Mater. Charact. 107, 220\u0026ndash;227 (2015).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eChen, J. \u003cem\u003eet al.\u003c/em\u003e Interfacial microstructure and mechanical properties of 316L /CuSn10 multi-material bimetallic structure fabricated by selective laser melting. Mater. Sci. Eng. A 752, 75\u0026ndash;85 (2019).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eZhang, M., Yang, Y., Wang, D., Song, C. \u0026amp; Chen, J. Microstructure and mechanical properties of CuSn/18Ni300 bimetallic porous structures manufactured by selective laser melting. Mater. Des. 165, 107583 (2019).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eHan, D. \u0026amp; Lee, H. Recent advances in multi-material additive manufacturing: methods and applications. Curr. Opin. Chem. Eng. 28, 158\u0026ndash;166 (2020).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eLiu, S. \u003cem\u003eet al.\u003c/em\u003e Effect of Cooling Rate on Microstructure and Grain Refining Behavior of In Situ CeB6/Al Composite Inoculant in Aluminum. Metals 7, 204 (2017).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eAli, M. \u003cem\u003eet al.\u003c/em\u003e Effect of cooling rate and composition on microstructure and mechanical properties of ultrahigh-strength steels. J. Iron Steel Res. Int. 26, 1350\u0026ndash;1365 (2019).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eKeshavarzkermani, A. \u003cem\u003eet al.\u003c/em\u003e An investigation into the effect of process parameters on melt pool geometry, cell spacing, and grain refinement during laser powder bed fusion. Opt. Laser Technol. 116, 83\u0026ndash;91 (2019).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003ePathania, A., Subramaniyan, A. K. \u0026amp; Nagesha, B. K. Influence of post-heat treatments on microstructural and mechanical properties of LPBF-processed Ti6Al4V alloy. Prog. Addit. Manuf. 7, 1323\u0026ndash;1343 (2022).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eHemmati, I., Ocel\u0026iacute;k, V. \u0026amp; De Hosson, J. Th. M. Dilution effects in laser cladding of Ni\u0026ndash;Cr\u0026ndash;B\u0026ndash;Si\u0026ndash;C hardfacing alloys. Mater. Lett. 84, 69\u0026ndash;72 (2012).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eLiu, K., Li, Y., Wang, J. \u0026amp; Ma, Q. Effect of high dilution on the \u003cem\u003ein situ\u003c/em\u003e synthesis of Ni\u0026ndash;Zr/Zr\u0026ndash;Si(B, C) reinforced composite coating on zirconium alloy substrate by laser cladding. Mater. Des. 87, 66\u0026ndash;74 (2015).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eZhu, S., Chen, W., Zhan, X., Ding, L. \u0026amp; Wang, E. Optimization of dilution rate of laser cladding repair based on deep learning. Int. J. Adv. Manuf. Technol. 110, 1471\u0026ndash;1484 (2020).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eCox, B., Ghayoor, M., Pasebani, S. \u0026amp; Gess, J. Tracking of Marangoni driven motion during laser powder bed fusion. Powder Technol. 425, 118610 (2023).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eChoo, H. \u003cem\u003eet al.\u003c/em\u003e Effect of laser power on defect, texture, and microstructure of a laser powder bed fusion processed 316L stainless steel. Mater. Des. 164, 107534 (2019).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eCherry, J. A. \u003cem\u003eet al.\u003c/em\u003e Investigation into the effect of process parameters on microstructural and physical properties of 316L stainless steel parts by selective laser melting. Int. J. Adv. Manuf. Technol. 76, 869\u0026ndash;879 (2015).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eZhang, M. \u003cem\u003eet al.\u003c/em\u003e Fatigue and fracture behaviour of laser powder bed fusion stainless steel 316L: Influence of processing parameters. Mater. Sci. Eng. A 703, 251\u0026ndash;261 (2017).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eNippes, E. F. \u0026amp; Ball, D. J. Copper-Contamination Cracking: Cracking Mechanism and Crack Inhibitors.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eRao, S. \u0026amp; Al-Kawaie, A. Y. Copper Contamination Cracking in Austenitic Stainless Steel Welds.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eAndreau, O. Influence of the position and size of various deterministic defects on the high cycle fatigue resistance of a 316L steel manufactured by laser powder bed fusion. Int. J. Fatigue (2021).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003edu Plessis, A. \u0026amp; Beretta, S. Killer notches: The effect of as-built surface roughness on fatigue failure in AlSi10Mg produced by laser powder bed fusion. Addit. Manuf. 35, 101424 (2020).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eSnow, Z. \u003cem\u003eet al.\u003c/em\u003e Analysis of factors affecting fatigue performance of HIP\u0026rsquo;d laser-based powder bed fusion Ti\u0026ndash;6Al\u0026ndash;4V coupons. Mater. Sci. Eng. A 864, (2023).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eHe, C., Ramani, K. \u0026amp; Okwudire, C. An intelligent Scanning Strategy (SmartScan) for Improved Part Quality in Multi-Laser PBD Additive Manufacturing. Addit. Manuf. (2022).\u003c/span\u003e\u003c/li\u003e\u003c/ol\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":true,"hideJournal":true,"highlight":"","institution":"","isAcceptedByJournal":false,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true},"keywords":"Additive manufacturing, bi-metallic interface formation, multi-material laser powder bed fusion, selective powder deposition, triply periodic minimal surfaces","lastPublishedDoi":"10.21203/rs.3.rs-4301742/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-4301742/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003eMulti-Material Laser Powder Bed Fusion (MM-LPBF) offers a novel approach for fabricating high-resolution components with both spatially tailored material properties and design by capitalizing on selective powder deposition (SPD) in conventional laser powder bed fusion (LPBF) processing. Advancements in multi-material additive manufacturing (AM), specifically MM-LPBF is now presenting a unique opportunity to reimagine additive manufacturing as we know today in terms of the local material assignment, AM-processing induced properties and design complexity which can help achieve functional requirements across multiple length scales.\u003c/p\u003e\n\u003cp\u003eIn this study, new MM-LPBF capability to manufacture a sheet-based gyroid structure composed of 904L stainless steel and bronze (CuSn10) is studied \u0026nbsp;for unique MM-LPBF signatures (e.g., melt pool characteristics, grain morphology and mechanical properties via intermittent micro-CT during flexural testing). The fracture mechanics of complex multi-material structures is investigated through multi-scale domain techniques, including mechanical testing (supported by digital image correlation (DIC), finite element analysis (FEA), and intermittent micro-CT), microstructural and morphological characterization of the bimaterial interface. This study analyzes the contribution of factors such as thermomechanical material compatibility, process-induced defects, cracking, porosity, and microstructure to determine the ultimate origin of failure and propagation patterns. Interface formation mechanisms are explored to elucidate process-structure-property framework for MM-LPBF. Findings from this study clearly demonstrate both the opportunity of MM-LPBF and current technological challenges to further advance the adoption of MM-LPF for a wide range of applications such as thermo-fluidic surfaces, solid-state energy storage, and biodegradable implants, among others.\u003c/p\u003e","manuscriptTitle":"Re-Imagining Additive Manufacturing through Multi-Material Laser Powder Bed Fusion","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2024-04-29 12:12:01","doi":"10.21203/rs.3.rs-4301742/v1","editorialEvents":[{"type":"communityComments","content":0}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"df421296-f55a-43df-9575-30e36b62b8f6","owner":[],"postedDate":"April 29th, 2024","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"posted","subjectAreas":[{"id":31163923,"name":"Physical sciences/Engineering"},{"id":31163924,"name":"Scientific community and society/Business and industry/Engineering"}],"tags":[],"updatedAt":"2024-06-10T13:36:35+00:00","versionOfRecord":[],"versionCreatedAt":"2024-04-29 12:12:01","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-4301742","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-4301742","identity":"rs-4301742","version":["v1"]},"buildId":"qtupq5eGEP_6zYnWcrvyt","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}