Multi Scale Analysis of Modified AZ61 Alloy Evolution of β-Mg17Al12 Phase and Structure–Property Correlation

Multi Scale Analysis of Modified AZ61 Alloy Evolution of β-Mg17Al12 Phase and Structure–Property Correlation | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Research Article Multi Scale Analysis of Modified AZ61 Alloy Evolution of β-Mg17Al12 Phase and Structure–Property Correlation Amit Tiwari, Aman Sharma, Sasmita Nayak, ginika mahajan This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-7619268/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 Optimizing the microstructure is one of the key processes to achieve the desired mechanical properties for magnesium alloys, such as the AZ61 alloy, which is extensively used in lightweight applications. This study further investigates advanced image processing of the β-Mg 17 Al 12 phase, a crucial intermetallic compound that determines strength and ductility. We developed a novel characterization approach that integrates high-resolution microscopy with automated image segmentation and quantitative analysis to enhance the characterization of the morphology, distribution, and volume fraction of the β-Mg 17 Al 12 phase. The AZ61 alloy underwent controlled thermo-mechanical processing to produce a modified form, resulting in the introduction of refined microstructural features. Furthermore, image analysis indicated significant microstructural evolution, including a homogeneous distribution and coarsening suppression of the β-Mg 17 Al 12 phase, based on process modification. The novelty of this study lies in our application of an image processing technique to the actual images of the sample's cross-sectional area, which allowed us to analyze the β-Mg 17 Al 12 phase effectively and understand how it contributes to optimizing the properties. It establishes a new baseline in accuracy and efficiency for mapping microstructural features that influence mechanical performance. DSC analysis was conducted to study the kinetics of phase transformation, employing advanced imaging techniques such as Small-Angle Neutron Scattering (SANs), solidification thermal mapping, and temperature distribution studies to analyze microstructural evolution. Small-Angle Neutron Scattering (SANs) Grain refinement β-Mg17Al12 phase Microstructure analysis DSC analysis Figures Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 Figure 7 Figure 8 Figure 9 Figure 10 1. Introduction The use of magnesium alloys is becoming increasingly prevalent among manufacturers as a means of meeting the ever-growing demand for lightweight applications. Mg alloys, however, exhibit minimal plastic deformation by dislocation due to the formation of a strong basal texture [ 1 ]. This occurs because there are no slip systems present, and the basal texture is robust. Mg also demonstrates isotropy in movement. Various approaches have been employed to improve the ductility of magnesium alloys [ 2 ]. These methods include raising the temperature, refining the grain, altering the mechanical behavior, and modifying the texture. Among the different types of magnesium alloys, Mg-Al is the most common. They are part of the wrought magnesium alloy family and are relatively inexpensive, offering intermediate strengths, acceptable ductility, and reasonable corrosion resistance. The flexibility of certain AZ, AM, and AE magnesium alloys is particularly noteworthy. For example, the AZ31 and AZ61 alloys belong to the AZ family of magnesium alloys and are characterized by their exceptional flexibility, strength, and resistance to corrosion [ 3 ]. Most magnesium-aluminium alloys have an aluminium content of less than 10% by weight. The presence of the β-phase, namely β-Mg 17 Al 12 , in the microstructure of the magnesium alloy cast at a moderate cooling rate is caused by nonequilibrium solidification. The proportion of the β-phase increases in magnesium-aluminium alloys as the amount of aluminium in the alloy is raised [ 4 ]. Micro alloying elements including Ti, Bi, Sb, Sn, and Sr, together with rare earth (RE) elements, have the potential to change the morphology of the β-Mg 17 Al 12 phase. These components have the ability to alter the amount, dimensions, dispersion, and direction of the β-phase [ 5 ]. Additionally, the mechanical properties of the material are enhanced as a result of micro alloying since it refines the α-Mg grains. The micro alloying elements hinder the growth of the grains and β-Mg 17 Al 12 phase because they are concentrated at the solid-liquid interfaces during the solidification process [ 6 ]. Consequently, the α-Mg matrix's grains undergo refining. The second phase can be formed when magnesium is combined with specific alloying components. The overall quantity of β-Mg 17 Al 12 is reduced and the dispersion of this phase is improved as a consequence of this rivalry, which decreases the efficiency of the combination of the Mg and Al elements. Al 2 Ca, Mg 3 Bi 2, Mg 3 Sb 2 and A1-RE are examples of the low-content second phases in the alloy that can be seen as needles or particles [ 7 – 10 ]. Both researchers and industry professionals are interested in re-refining magnesium alloy grains due to the advantages offered by a more refined microstructure. Numerous methods exist to control the size of metal and alloy grains during solidification. Increasing the cooling rate during solidification is the primary approach [ 11 ]. However, this process is incompatible with most industrial castings, especially those with thicker walls. Alternatively, alloying elements can be introduced during the melting process. The limited solubility of these elements in solidified grains leads to their entrapment at the solid/liquid boundary. The formation of nucleated grains is hindered when the liquid is rich in solute atoms [ 12 – 14 ]. Different alloying elements have varying abilities to restrict grain growth. To predict the characteristics and performance of the final product, a thorough examination of the material's microstructure during production and any subsequent heat treatments is essential. Controlling the microstructure requires familiarity with its constituent phases and their macroscale effects based on composition, form, and specific qualities. Optimizing material properties for a particular application depends on this knowledge, which is crucial across various production processes [ 15 ]. A detailed understanding of digital microstructure, which involves phenomena from visualization and characterization of microstructures to mechanical analysis based on different grain or phase structures, is important in the context of materials science, as digital microstructure contains a wealth of relevant digital data that can be used in numerous practical applications [ 16 – 18 ]. So far, significant attention and effort have been dedicated to the development of tools and procedures that enable users to fully utilize digital microstructures (DMs) in their development workflow. Digital microstructure has been employed to predict or analyze a wide range of microstructure-sensitive properties, including mechanical characteristics such as strength and ductility, thermal properties, corrosion resistance, recrystallization, and phase transformation [ 19 – 20 ]. AZ 61 wrought magnesium alloys exhibit poor formability and low ductility at room temperature due to their hexagonal close-packed (hcp) structure. The process of grain refinement for wrought magnesium alloys designated as AZ 61 is not yet fully understood. Therefore, it is essential to investigate the effects of smaller additions of grain refining materials and ultimately determine the optimal composition for achieving the highest possible level of grain refinement. An enhancement in the grain refinement method is necessary to produce an AZ 61 magnesium alloy with exceptional mechanical properties. Finding a solution to improve the ductility and strength of AZ 61 alloys through the stir-casting process by refining grains is challenging. Utilizing novel image analysis and processing techniques, this work aims to investigate the microstructure of a modified AZ61 alloy with the goal of leveraging the microstructural features and mechanical strength, as well as their close relationship with the microstructure and phase. Previous literature suggests that this processing method and composition development can significantly enhance the properties of these alloys. The enhancements arise from fine-tuning the microstructure and age-hardening it with small alloying elements. This study is based on the premise that creating an AZ61-based alloy with improved properties can be achieved through a combined approach involving grain refinement and precipitation hardening. To this end, small amounts of Sc and Ca were added to traditional AZ61 to form new alloys. Scandium is used for its capacity to enhance the cast structure by inhibiting dendrite growth and to facilitate age-hardening through the formation of Al3Sc precipitates. Conversely, calcium aids in the development of Mg 2 Ca and Al 2 Ca phases, which are recognized to promote age-hardening. Such modifications are made during the stir casting process, which enables structural refinement by minimizing diffusion lengths for alloying species to optimize age-hardening. This research addresses the limitations of existing traditional methods of microstructural analysis. Most commercial software are not sufficiently effective in recognizing and quantifying microstructure. To resolve this issue, we employ an automated image processing approach capable of detecting grain sizes, phase proportions, and interfacial characteristics. These analyses encompass the kinetics of phase transformation, as well as the phase-property relationship, allowing for a comprehensive analysis of the performance of the modified AZ61 alloy. 2. Experimental Procedure The elements contained in AZ61 alloys and minor additions of elements during casting help characterize the advantages of stir casting. The nominal composition of the modified alloy was Mg-6 Al-1 Zn-0.5 Mn-0.5 Ca-0.2 Sc. A chemical balance was used to measure the weight of dried ingredients. Melting was conducted in a resistive heating pot furnace equipped with a stirrer. Magnesium and aluminum were poured into the melting pot once the temperature reached 750°C, followed by zinc, manganese, and calcium, before finally adding scandium. For each melt, 10 wt. % more elements than theoretically necessary were introduced to account for oxidation losses. Stirring at 600 rpm was applied for 15 minutes to create a homogeneous melt before pouring it into preheated metal molds (200 mm × 20 mm × 20 mm) at 200°C to minimize the chilling effect. A multi-scale experimental study was conducted to investigate the effect of various thermal/mechanical approaches on the phase evolution analysis of the AZ61 magnesium alloy (formability aspects, β-Mg 17 Al 12 phases, dendritic morphology, and microstructural aspects) to obtain the inherent structural characteristics. Casting the alloy samples into the desired molds, followed by rolling to a thickness of 0.5 mm at 100°C, 200°C, 300°C, and 400°C resulted in differing degrees of alignment of the β-Mg 17 Al 12 phase. Mechanical grinding of the samples in stages up to 2500 emery paper is carried out under continuous water flow to remove ground debris and for sample cooling; this is thereafter followed by optical metallographic analysis. The samples are then polished on cloth with diamond suspension from 9 µm to 1 µm and with alumina suspension compound of 0.5 µm (successively finer), and cleaned in an ethanol bath and sonicated for about 10 minutes to remove loose particles from the surfaces following grinding. After sonication-assisted drying in ethanol, they are etched with a solution of (25 ml ethanol + 5 ml acetic acid + 1.5 gm picric acid + 10 ml distilled water). The etching is performed for about 20 seconds, and the etching time is also optimized with the samples if needed. A post-etch water rinse is applied to the above samples. Optical microscopy and Small Angle Neutron Scattering (SANS) are used to shed light on nanoscale structural alterations of the samples. Post-processing was performed on the 2D view intensity profile before the beam-based therapy, analyzing the texture/morphology evolution by extracting log-scaled intensity patterns from images and diagrams. Thermal maps from 550°C to 100°C were created to study the solidification and thermal gradient, which are key for dendrite growth and solute segregation studies. Secondary phase evolution and grain refinement were also confirmed through computational analyses of solidification fields and boundary temperature distributions. 3. Results and Discussion 3.1. Microstructure examination of modified AZ 61 alloy Figure 1 a illustrates the characteristic cellular dendritic micromorphology of the as-cast AZ61 alloy microstructure, which is unique to the stir-cast modified AZ61 alloy. This framework develops from constitutional supersaturation during the solidification process in high-speed extrusion that suppresses dendrite growth. The as-cast samples display two primary phases: the α-Mg matrix and the β- Mg₁₇Al₁₂ phase situated at the grain boundaries. The microstructure is refined through the rapid stirring of alloy constituents during casting, which imparts mechanical strength to the cooled metal. After rolling at 100°C, Fig. 1 b reflects the slightly recrystallized grain size and partially equiaxed structure, while Sc can enhance mechanical properties by modifying the Mg₁₇Al₁₂ phase. Improved mechanical properties, second-phase dispersion, and anodized surface uniformity are characteristic features of the refined equiaxed grain structure. It is known that rolling at 200°C leads to grain refinement; Fig. 1 c showcases this phenomenon, followed by peak hardness due to an increased volume fraction of the second phase. The in situ formed dense plate-like Mg₂Ca phase during casting significantly enhances hardness, and it has been previously confirmed by X-ray diffraction that the presence of 0.5 wt% Ca results in considerable grain refinement. The increased microhardness of Mg₂Ca phases at 200°C results in improved rolling properties. Figure 3 , Processing / Microstructure / Hardness relationship: as the solute supersaturated solid solutions formed at short aging times decompose, a maximum in Vickers hardness occurs at 200°C. The grain size decreases with rolling at 300°C and 400°C; however, excessive softening at higher temperatures leads to a further decrease in hardness and yield strength, emphasizing the importance of temperature in optimizing properties (Fig. 1 d and 1 e). 3.2. Thermal mapping with temperature gradient of modified AZ61 alloy The thermal maps of AZ61 alloy at various temperatures reveal the complex evolution of its microstructure through the detection of its primary and secondary phases, grain boundaries, and grain refinement. These alterations in microscale structure significantly impact the properties of the alloy at the material size level, including corrosion resistance, thermal stability, and deformation behavior. In the Cast Condition (Fig. 2 b), the thermal map shows a heterogeneous microstructure with coarse α-Mg grains coarsely separated by intermetallic β-Mg 17 Al 12 phases at the grain boundaries. The marked tendency toward the brittle β-phase indicates a susceptibility to cracking upon deformation and a tendency for lower corrosion resistance due to galvanic coupling with the α − Mg matrix. This is caused by the solidification process, which encourages coarse grain coarsening and β-phase particle segregation. Rolled at 100°C (Fig. 2 b), the material displays coarse grain structures with some grain boundary alignment due to mechanical rolling, as suggested in the map. The β-Mg 17 Al 12 phases remain stable, and only their fragmentation begins, which slightly decreases the microstructural heterogeneity. This is influenced by the persistence of coarse grains and grain boundary phases in thermal stability, thus hindering improvements in isotropy. Rolled at 200°C (Fig. 2 c), dynamic recrystallization is observed in this micrograph, appearing as equiaxial grains that form uniformly. These refined grain boundaries and dispersed β-phase contribute to the improved stability of the phases and inhibited grain growth. This small grain structure enhances resistance to thermomechanical processes through reinforcement against creasing and improved homogeneity. Rolled at 300°C (Fig. 2 d), the grain structure becomes finer, with significant dissolution of the β-phase. This improvement enhances thermal stability and reduces the risk of intergranular corrosion by ensuring consistent grain boundaries and phase distribution. Rolled at 400°C (Fig. 2 e), thermal mapping reveals widespread grain boundary stabilization and near-total β-Mg 17 Al 12 dissolution. The fine grain structure promotes a more homogenous composition, improves oxidation resistance, and enhances thermal stability while reducing stress concentrations from phases. The phase and grain boundary analysis of the AZ61 alloy aids in understanding its structural integrity and stability under specific conditions. The knowledge of these changes can be leveraged to maximize the potential usefulness of the materials in applications where thermal stability, corrosion resistance, and processability are essential. 3.3. Histogram plot of modified AZ61 alloy From the results, it is determined that the histogram plot can provide unique insights into the microstructure of the AZ61 alloy that are very difficult to observe with a conventional microscope. Histograms of pixel intensity distributions (Fig. 3 ) were well correlated with the microstructure tonal variation data, showing significant differences in shapes, sizes, and percentage distributions. The x-axis represents pixel intensity (0-255), while the y-axis represents pixel number, with different patterns reflecting the alloy's heterogeneity. In (Fig. 3 a), a mean intensity of 147.875 and a standard deviation of 72.188 reveal a wide intensity range, indicating a complex microstructure characterized by a mixture of phases. A broad distribution suggests a mixture of α-Mg and β-Mg 17 Al 12 phases with varying grain characteristics, which are associated with improved strength through grain boundary precipitation hardening. Conversely, (Fig. 3 b) has an average intensity of 150.037 and a lower standard deviation of 53.353 compared to (Fig. 3 a), implying a more homogeneous microstructure with uniformly distributed secondary phases and grain size. This ordering results in enhanced yield strength and mechanical properties. Histograms in (Fig. 3 c-e) represent narrower intensity distributions with mean intensities ranging from 85.504 to 101.226 and standard deviations from 20.111 to 27.717. These indicate a similar grain size and a lower amount of β-Mg 17 Al 12 phase, leading to reduced strength and higher ductility and toughness. The analysis highlights that adjustments to the processing of microstructures can optimize the mechanical properties of the AZ61 alloy, effectively balancing strength and ductility. Narrow and wide intensity distributions correlate with uniform and complex grain structures, respectively. 3.4. Surface Profile of modified AZ61 alloy The simulated grain-refining microstructures also directly reflect the distribution of the secondary phase and the surface hardness in AZ61 magnesium alloy (see Fig. 1 to 3 ). The analysis of Fig. 4 a and Fig. 4 b illustrates the features of the alloy through polyhedra based on the distance in pixels and volume change across the alloy's composition. The variations in gray values indicate inconsistencies in surface hardness, possibly due to the non-uniform distribution of alloy constituents, diversity in microstructure, and processing methods, such as heat treatment. The peaks in these graphs represent areas of sheen that the coarser crystallization of lower hardness, revealed in the troughs, cannot maintain. Grain refinement can significantly improve the mechanical properties of magnesium alloys. As shown in Fig. 4 c and Fig. 4 d, the finely processed grains diminish the characteristically needle-like structures of the magnesium grains, leading to a refined structure that enhances hardness and strength through the Hall-Petch effect, whereby smaller grains inhibit dislocation motion. However, the weakening of the alloy increases with the formation of relevant grain boundary structures; secondary phases like β-Mg 17 Al 12 often emerge throughout the phase network at the grain boundary, allowing increased dislocation movement that creates additional slip lines, as suggested by the higher gray values shown in Fig. 4 e. These phases also enhance wear resistance and mechanical strength. Poor microstructure uniformity and hardness can be observed in cast magnesium alloys, underscoring the importance of optimized processing conditions to promote uniformity, refined microstructures, and performance. 3.5. Analysis of Grain size distribution of optical micrograph of modified stir AZ61 alloy It illustrates the variation in grain size of stir-cast AZ61 alloy at various aging temperatures. Figure 1 (b-e): Schematic representation of the measured and obtained results in Fig. 5 . In contrast, the grain size in Fig. 5 a ranged from approximately 40 µm to 160 µm, with most grains between 60 and 100 µm; this broader distribution indicates a coarser microstructure expected to exhibit lower hardness due to reduced grain boundary density. The diminished hardness is attributed to the uneven distribution of grain sizes, likely resulting from insufficient grain refinement. Microstructure sizes are generally smaller than those observed in as-cast metal, as seen in Fig. 5 b, which shows the grain size primarily ranging between 8 and 16 µm, indicating that grain refinement, microstructure homogenization, and dissolution of secondary phases occur during heat treatment. Numerous studies have demonstrated that such processes lead to superior mechanical properties; for instance, hardness is expressed by the Hall-Petch relationship, where a higher density of finer grains hinders dislocation movement, resulting in a stronger material. As shown in Fig. 5 c and 5 d, the grain size distribution is relatively uniform, mostly within the 4 to 8 µm range; this may be due to effective heat treatment and alloying with elements like Al or Ca, which significantly assist in refining the microstructure. The resulting small-grained equiaxed structure enhances hardness, ductility, and overall wear resistance. Another important strengthening phase is the well-known Mg17Al12 phase located at the grain boundaries, which greatly enhances resistance to deformation by impeding dislocation movement. Consequently, the development of finer grain structures leads to increased hardness, tensile strength, and improved mechanical properties of the AZ61 alloy. 3.6. 3D feature maps of an optical micrograph of modified stir AZ61 alloy Analysis insights for 3D feature maps of modified AZ61 magnesium alloy under different conditions. The maps show the evolution of secondary phases and microstructural features during thermal and mechanical treatments of the alloy. As Cast Condition (Fig. 6 a), feature map shows high randomness, suggestive of a heterogeneous nature in microstructure with considerable porosity and coarse secondary phase β-Mg 17 Al 12 , Large grains and inhomogeneous precipitation are structure characteristics that are common with as cast AZ61 alloys. This arrangement, in turn, affects properties such as low ductility and moderate strength. Rolled at 100°C (Fig. 6 b), the feature map exhibits a decrease in the amplitude of the peaks indicating enhanced homogeneity and partial recrystallization. This leads to the formation of fine secondary phases along the rolling directions which increases the strength, however, not very much improves the ductility. Rolled at 200°C (Fig. 6 c), the increased rolling temperature manifests in the further refined microstructure and dispersion of the secondary phase. Some dissolution of the secondary β-Mg 17 Al 12 phase takes place which also helps in grain boundary pinning. These conditions offer optimized mechanical properties combining increased ductility with strength. Rolled at 300°C (Fig. 6 d), the feature map smooths further and illustrates extensive grain refinement and recrystallization. Destruction of second-phase precipitates causing excellent ductility with retained strength. Rolled at 400°C (Fig. 6 e): The feature map is consistent, indicating that the observed changes are due to extending grain growth and a decrease in dislocation density. There are not many secondary phases left offering good ductility but low yield strength. This data is critical for predicting and optimizing material properties like strength, ductility, or thermal stability for AZ61, offering industry-customized processing within the automotive and aerospace domains. 3.7. Solidification of alloy and dendrite formation analysis of modified AZ61 alloy in cast condition Figure 7 a shows the dendrite formation and solidification temperature field, which can help researchers analyze the complex thermodynamic and kinetic environment during the solidification of AZ61 magnesium alloy. The temperature gradient, observed from 550°C (yellow region) to below 100°C (dark red region) in the direction of heat extraction, substantiates the previously noted effect on dendritic nucleation and growth. This gradient also suggests a competition between thermal and constitutional undercooling that dictates the stability of dendritic growth. Above collectors, the dendrites are intricate, indicating the functionality of columnar growth as the high-temperature gradients in the upper regions favor directional solidification. However, with decreasing temperature in the lower zones the effect of thermal gradients and constitutional undercooling leads to epitaxial growth changing to a more equiaxed dendritic structure. This transition zone is where mechanical integrity of the material is altered since defects can occur in that zone if poorly controlled during solidification. It can be observed how solute elements (for example, aluminium and zinc) are segregated into the interdendritic regions during solidification. These factors control the solidification path such that they decrease the melting point locally and leave some residual liquid pockets between the dendritic arms. Last to solidify are such pockets, which form β-Mg 17 Al 12 phases that segregate along grain boundaries. These phases can serve as sites of crack initiation under mechanical loading and also increase susceptibility to localized corrosion, particularly in chloride-rich environments. The temperature map highlights areas with higher gradients that contribute to finer dendritic arm spacing (secondary arm spacing, SAS). It has also been demonstrated that finer SAS results in improved mechanical isotropy, reduced porosity, and enhanced phase homogeneity during processing. However, dendrites with a coarser structure are likely to form in areas of low thermal gradient, leading to anisotropic characteristics and consequently lower ductility and fatigue resistance. The various temperature zones provide valuable insight into the cooling curve of the alloy and the time required for solidification in each region. This results in rapid nucleation in the upper regions, where cooling is more rapid and dendritic growth is limited, while slower cooling in the lower regions encourages the formation of well-structured larger dendritic arms. This principle can be applied in casting process design, such as strategically positioning chillers or heat sources in different sections of the mold, to manage the cooling rate and achieve desired microstructural features. This signifies the necessity for controlled thermal gradients and cooling rates when casting AZ61 alloy. Utilizing advanced data processing techniques, such as directional solidification or controlled cooling methods via computational simulations, allows for optimization of the microstructure. This leads to fewer casting defects, e.g., segregation and porosity, which enhances the corrosion resistance, thermal stability, and mechanical properties of the material. Dendritic growth and secondary phase formation are meticulously controlled, enabling customized property enhancement and reliability under severe operational conditions. (Fig. 7 b) shows an internal cross section of dendrite tip length at an equiaxed temperature within the modified AZ61 alloy in its as-cast condition. Note that temperature values vary between 600°C and below 100°C, indicating the non-linear cooling that occurs during casting. Drastic temperature drops are observed across specific boundary indices, highlighting regions with high thermal gradients that are crucial for dendrite nucleation and growth. The changes in the cooling curve reflect the local solidification rate, which affects the secondary arm spacing (SAS) of the dendrites. Finer dendritic structures form in regions with faster cooling, while coarser dendritic arms are found in broader boundary regions with slower cooling, resulting from variations in SAS. The temperature across the boundary is non-uniformly distributed, which is particularly significant as it relates directly to micro segregation. Alloying elements such as aluminum and zinc are expelled from the primary α-Mg phase, becoming concentrated in the interdendritic regions, which can also facilitate the formation of local secondary β-Mg 17 Al 12 phases. Such segregation negatively impacts the structural homogeneity of the metal, making it more susceptible to stress corrosion cracking and galvanic corrosion. Additionally, steep temperature gradients influence dendrite morphologies. Columnar dendritic growth is favored in higher gradients while equiaxed structures occur in lower gradients. This structural variation contributes to the mechanical isotropy and thermal stability of the alloy. Therefore, this study demonstrates that cooling rates in the casting process must be controlled. This notably aids in mitigating segregation, generating dendritic structures with refined morphology, and consequently enhancing the overall mechanical and corrosion-resistant characteristics of the AZ61 alloy. Such information is valuable for optimizing casting conditions in industry. The current analysis can assist in designing magnesium alloys with improved performance for significant applications, such as automotive and aerospace components, thereby integrating experimental observations with computational modeling. 3.8. Small- angle neutron scattering of modified AZ61 alloy under various conditions A detailed account of the nanoscale structural evolution, phase orientation, and geometry of AZ61 alloy under various dispersive mechanical and thermal conditions was examined through Small-Angle Neutron Scattering (SANS) intensity patterns. This analysis is fundamental to understanding the dynamic evolution of the microstructural features and their impact on the mechanical and physical properties of the alloy. In the As-Cast Condition (Fig. 8 a), the as-cast SANS pattern shows a broad spot around a distinct peak center, suggesting a large secondary phase, β-Mg 17 Al 12 , distributed over irregular spacing. The large diffuse halo indicates substantial heterogeneity and an absence of crystalline orientation. The lack of strong anisotropic scattering features means there is little texturing in the as-cast state. Resulting from rapid solidification and thermal gradients, solute segregation occurs at the grain boundaries. Therefore, from the observed microstructural geometry, the phase continuity is poor, and distortion leads to rough stress distribution, which is crucial for fracture toughness. When rolled at 100°C (Fig. 8 b), the central intensity decreases due to the partial fragmentation of secondary phases. Texture evolution of the grains and sub-grains, with a starting alignment, is revealed by the scattering pattern. At this temperature, mechanical deformation effectively breaks up β-Mg 17 Al 12 phase clusters, improving the uniformity of phase distribution. However, the lower deformation temperature limits complete recrystallization, and some microstructural anisotropy remains. When rolled at 200°C (Fig. 8 c), a cross-like feature emerges in the SANS intensity map, indicating alignment of crystalline structures along the rolling direction. This phenomenon is evidence of dynamic recrystallization, involving the refinement of sub-grains, followed by the dissolution of secondary phases into the matrix, such as β-Mg 17 Al 12 . The nanoscale alignment indicates a better compromise between strength and ductility, as well as reduced stress concentrations in smaller secondary phases. This condition also promotes grain boundary strengthening, improving the alloy’s overall protection against intergranular corrosion. When rolled at 300°C (Fig. 8 d), the scattering pattern widens at 300°C, and the intensity distribution becomes weak and diffuse, suggesting that the grain structure is significantly refined and the β-phase extensively dissolved. An isotropically buffered nanostructure resulting from full recrystallization and grain rotation leads to a uniform scattering distribution. The material geometry shifts to equiaxed grains, aiding in resisting localized corrosion and decreasing flow-induced anisotropy. This stage reveals a fine microstructure, indicating increased thermal stability. When rolled at 400°C (Fig. 8 e), the SANS pattern exhibits lower intensity and highly symmetric scattering, reflecting full recrystallization and a minimal amount of residual second phases. Grains are fine and equiaxed under these conditions, resulting in a highly homogeneous structure that decreases internal stresses and increases ductility. However, such significant grain growth and near-complete dissolution of strengthening phases may decrease the alloy’s tensile strength. The evolution of the SANS patterns provides key insights into how the distribution of the secondary phase, crystallographic texture, and nanoscale geometry interact. The decay of anisotropic trapped features and the increase in the width of the scattering halo clearly indicate the disappearance of the β-Mg 17 Al 12 phase and the evolution from a textured to a near-isotropic microstructure. The examination further illustrates the significant impact of rolling temperature on dynamic recrystallization, resulting in the formation of finer grains and increased uniformity of the phases at elevated temperatures. In this study, SANS is employed to obtain information that would be challenging to achieve using traditional microscopy; the combination of SANS and other techniques ensures that the structure can be analyzed and thoroughly discussed in more detail. This analysis also helps optimize nanoscale features to improve mechanical and thermal properties, such as resistance to fatigue, corrosion, and thermal stability, by addressing processing conditions, as evaluated on nanoscale features. The patterns also highlight the need for a balance between recrystallization and grain growth to impart optimized material properties, enabling the development of high-performance components for lightweight automotive structures and aerospace applications. 3.9. X-ray diffraction (XRD) result of modified AZ61 alloy under cast and rolled condition A detailed structural analysis is conducted using the X- ray diffraction test to provide clear insights into the phases developing in the stir cast alloys under different conditions (Fig. 9 ). The XRD results indicate the following: the primary phase is α- Mg matrix (Mg- Al solid solution), β-Mg 17 Al 12 , Mg 2 Ca. The XRD analysis suggests that a small amount of the element Ca may dissolve in the Mg matrix, and any excess Ca would precipitate from the Mg 2 Ca phases. It was rarely found in AZ 61, containing 0.2% Sc, 0.5% Ca, and 0.5% Mn, which is higher than 1% Mn due to the scarcity of the Ca element. A phase of Mn was not observed, likely because the amount of the Mn phase was small and did not reach the detection limit of the diffractometer. Scandium amounts to 0.2% by weight in this aluminum alloy. This predicts the precipitation of Al 3 Sc upon thermal exposure. It is worth mentioning that the possible Al 3 Sc phase did not exist in the stir- cast alloy, as shown by the XRD analysis. There could be two reasons for this. Initially, the Al 3 Sc concentration could have been so minor that the peak could not be distinguished due to background noise. The second reason may be that Al 3 Sc is dissolved in Mg 2 Ca because of the different crystal structures. However, the precipitation of the secondary β-Mg 17 Al 12 phase in its casting condition (as revealed in Fig. 9 b) contributes to enhancing the mechanical strength of the alloy due to the higher concentration of completely dissolved Al in the magnesium matrix. The microstructure of the treated sample transforms through a rolling treatment, resulting in an increased hardness number. Figure 9 a and 9 b demonstrate that two T6- treated samples presented the same phase constitution stage; in other words, the α- Mg and the intermetallic β-Mg 17 Al 12, but the process of microstructure evolution in the two T6- treated samples was the same yet varied depending on the grain size. A dendritic structure, resulting from the solidification of molten metal, developed with a slow cooling rate, and α- Mg and β-Mg 17 Al 12 were present in the as- cast sample. 3.10. Differential scanning calorimetric study (DSC) of cast condition AZ 61 alloy A precipitation kinetics assessment, indicated by the forming peak in (Fig. 10 a), was conducted to further understand the aging response of the AZ61 alloy through a DSC study. Fewer than the exothermic peak at 83.5°C, there are smaller peaks at various temperatures. From the XRD pattern of the experimental alloy, it was observed that small peaks can be recognized at approximately 125°C and 175°C, and the exothermic peaks observed in the DSC heating cycle suggest that new phases were generated. The activation energy for the larger peak appearing at 83.5°C is calculated using the Nagasaki-Maesono relationship [ 3 ], which is derived from the Arrhenius equation 𝑙𝑛 [∆𝐶𝑝(𝑊−𝑤)] = ln 𝐴−𝐸/𝑅𝑇. This corresponds to ln, where Δ Cp is heat capacity, W is the area under the peak, ‘w’ is the area of the shaded portion in (Fig. 10 b), E represents activation energy, and R stands for the universal gas constant. In (Fig. 10 c), the calculated activation energy is approximately 154.48 KJ/mol. The diffusion of aluminum at the grain boundaries in magnesium resulted in an activation energy of 144.5 KJ/mol [ 14 ]. Based on the DSC results, it is concluded that the diffusion of aluminum in magnesium limits precipitation during aging, and Mg 17 Al 12 precipitates form at 83.9°C with the highest transformation rate. 4. Conclusion In this study, the microstructure of the modified AZ61 alloy is optimized by examining the β-Mg 17 Al 12 phase using advanced image processing techniques. High-resolution imaging and automated image analysis enable precise quantitative characterization of the β-Mg 17 Al 12 morphology, size, and spatial distribution. Consequently, the modification process enhances the phase itself, refining it; therefore, the dispersion becomes more homogeneous and the average particle size smaller. Furthermore, quantitative analysis of the interactions among these phases clarifies their role in the alloy's performance and introduces a novel approach to microstructural analysis utilizing an image processing-assisted method. This approach deepens the understanding of microstructure-property relations and allows for the design of tailored magnesium alloys to meet specific engineering demands. Based on a multi-scale approach that combines advanced metallographic and thermal measurements, insights into the β-Mg 17 Al 12 phase evolution and its structure-property synergy are revealed for the modified AZ61 magnesium alloy. The as-cast microstructure exhibits a thermal gradient of 550°C to 100°C due to a high central SANS intensity, coarse dendrites, and strong segregation of β-Mg 17 Al 12 at grain boundaries. These features lead to localized stress concentrations and reduce uniformity. When the composite was rolled at 100°C, the β-Mg 17 Al 12 partially fragmented and the grains were moderately refined, giving more uniform phase distribution, which is evidenced by lower SANS intensity and initial textural alignment. 200°C Dynamic recrystallization led to equiaxed grains and decreased secondary arm spacing, promoting greater isotropy and phase connectivity. This state naturally increased ductility and reduced intergranular corrosion threats. The fine-grained microstructure and the uniform SANS scattering in the 300°C rolled material should also bring potential enhancements in the thermal stability and reduction of anisotropy. 400°C, the fully recrystallized and grain expanded structure resulted, which was also very homogeneous and suitable for ductility and corrosion resistance at the expense of tensile strength. The role of the β-Mg 17 Al 12 phase evolution and grain refinement are highlighted as the key factors in the alloy properties tailoring. This study outlines a framework that this work relies upon the incorporation of image processing for the optimized microstructural design, providing the groundwork for future studies aimed at producing lightweight alloys applicable for automotive and aerospace engineering industries. Declarations Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper. Funding This research did not receive any funding. Author Contribution Conceptualization: Amit Tiwari, Aman SharmaMethodology: Amit Tiwari, Sasmita NayakFormal Analysis and Investigation: Amit Tiwari, Ginika MahajanResources and Materials: Aman Sharma, Ginika MahajanData Curation and Image Processing: Sasmita Nayak, Amit TiwariWriting – Original Draft Preparation: Amit TiwariWriting – Review & Editing: Aman Sharma, Sasmita NayakVisualization (Figures, Graphs, and Image Analysis): Sasmita NayakSupervision and Project Administration: Aman Sharma Acknowledgement The authors wish to acknowledge the support received from the Suresh Gyan Vihar University while conducting the research. Data Availability The data that support the findings of this study are available from the corresponding author, upon reasonable request. References Arora, G. S., Saxena, K. K., Mohammed, K. A., Prakash, C., & Dixit, S. (2022). Manufacturing Techniques for Mg-Based Metal Matrix Composite with Different Reinforcements. Crystals , 12 (7), 945. https://doi.org/10.3390/cryst12070945 Baek, S., Kim, J., Min, D., & Park, S. S. (2023). Remarkably slow corrosion rate of high-purity Mg microalloyed with 0.05wt% Sc. Journal of Magnesium and Alloys , 11 (3), 991–997. https://doi.org/10.1016/j.jma.2022.08.003 Banerjee, M. K., Tiwari, A., & Kumar, N. (2023). Ageing characteristics of stir cast AZ 61 alloy with minor additions. Recent Patents on Engineering , 18 . https://doi.org/10.2174/1872212118666230609122741 Bian, M., Sasaki, T., Suh, B., Nakata, T., Kamado, S., & Hono, K. (2017). A heat-treatable Mg–Al–Ca–Mn–Zn sheet alloy with good room temperature formability. Scripta Materialia , 138 , 151–155. https://doi.org/10.1016/j.scriptamat.2017.05.034 Chang, W., Shen, Y., Su, Y., Zhao, L., Zhang, Y., Chen, X., Sun, M., Dai, J., & Zhai, Q. (2019). Grain refinement of AZ91 magnesium alloy induced by AL-V-B Master alloy. Metals , 9 (12), 1333. https://doi.org/10.3390/met9121333 Chaudry, U. M., Hamad, K., & Jun, T. (2022). Investigating the microstructure, crystallographic texture and mechanical behavior of Hot-Rolled pure MG and MG-2AL-1ZN-1CA alloy. Crystals , 12 (10), 1330. https://doi.org/10.3390/cryst12101330 Soni, P. K., Tiwari, A., Nayak, S., Vasnani, H., & Jha, S. K. (2024b). Ultrafine grain refinement and improved mechanical strength of compositionally modified AZ 61 alloy composite. In Advances in chemical and materials engineering book series (pp. 327–362). https://doi.org/10.4018/979-8-3373-0669-8.ch009 Chen, X., Zhang, D., Zhao, Y., Feng, J., Jiang, B., & Pan, F. (2020). Microstructure modification and precipitation strengthening for Mg–6Zn–1Mn–4Sn–0.5Ca through extrusion and aging treatment. Transactions of Nonferrous Metals Society of China , 30 (10), 2650–2657. https://doi.org/10.1016/s1003-6326(20)65409-7 Cheng, K., Zheng, Y., Sun, J., Zhao, Y., Wang, J., Yu, H., Zhao, D., Li, H., Zhou, J., Ma, Z., Wang, J., Guo, C., Wang, X., Zhang, L., & Du, Y. (2023). Investigation on the temperature-dependent diffusion growth of intermetallic compounds in the Mg-Al-Zn system: Experiment and modeling. Journal of Magnesium and Alloys . https://doi.org/10.1016/j.jma.2023.02.009 Tiwari, A., Kumar, N., & Banerjee, M. K. (2023). Effect of Hot Rolling on Microstructure and Mechanical Properties of Stir Cast AZ 61 Alloy with Minor Additions. Indian Journal of Science and Technology , 16 (24), 1810–1822. https://doi.org/10.17485/ijst/v16i24.302 Cho, D. H., Avey, T., Nam, K. H., Dean, D., & Luo, A. A. (2022). In vitro and in vivo assessment of squeeze-cast Mg-Zn-Ca-Mn alloys for biomedical applications. Acta Biomaterialia , 150 , 442–455. https://doi.org/10.1016/j.actbio.2022.07.040 Ding, Y., Shi, Z., Li, Z., Jiao, S., Hu, J., Wang, X., Zhang, Y., Wang, H., & Guo, X. (2022). Effect of CNT content on microstructure and properties of CNTs/Refined-AZ61 Magnesium matrix composites. Nanomaterials , 12 (14), 2432. https://doi.org/10.3390/nano12142432 Dong, X., Feng, L., Wang, S., Nyberg, E. A., & Ji, S. (2021). A new die-cast magnesium alloy for applications at higher elevated temperatures of 200–300°C. Journal of Magnesium and Alloys , 9 (1), 90–101. https://doi.org/10.1016/j.jma.2020.09.012 Tiwari, N. A. (2024). Prediction model for hardness and tensile strength of graphene reinforced AZ 61 alloy based composite using Metaheuristic Algorithm. Global Journal of Engineering and Technology Advances , 20 (3), 042–052. https://doi.org/10.30574/gjeta.2024.20.3.0167 R. Venkatesh, C. Ramesh Kannan, S. Manivannan, M. Vivekanandan, J. Phani Krishna, Amine Mezni, Saiful Islam, S. Rajkumar, “Synthesis and Experimental Investigations of Tribological and Corrosion Performance of AZ61 Magnesium Alloy Hybrid Composites”, Journal of Nanomaterials, vol. 2022, Article ID 6012518, 12 pages, 2022. https://doi.org/10.1155/2022/6012518 n.d . Huang, SJ., Subramani, M., Ali, A.N. et al. The Effect of Micro-SiCp Content on the Tensile and Fatigue Behavior of AZ61 Magnesium Alloy Matrix Composites. Inter Metalcast 15, 780–793 (2021). https://doi.org/10.1007/s40962-020-00508-0 n.d . Song-Jeng Huang, Murugan Subramani, Chao-Ching Chiang, Effect of hybrid reinforcement on microstructure and mechanical properties of AZ61 magnesium alloy processed by stir casting method, Composites Communications, Volume 25, 2021, 100772, ISSN 2452 – 2139, https://doi.org/10.1016/j.coco.2021.100772 . n.d. Liu, W., Jiang, B., Luo, S. et al. Mechanical properties and failure behavior of AZ61 magnesium alloy at high temperatures. J Mater Sci 53, 8536–8544 (2018). https://doi.org/10.1007/s10853-018-2125-7 n.d . Zhaohui Shan, Yixia Zhang,, Bin Shan Wang, Qiang Zhang, Jianfeng Fan; Microstructural evolution and precipitate behavior of an AZ61 alloy plate processed with ECAP and electropulsing treatment, Journal of Materials Research and Technology, Volume 19, July–August 2022, Pages 382–390 n.d. Jiangfeng Song, Jia She, Daolun Chen, Fusheng Pan, Latest research advances on magnesium and magnesium alloys worldwide, Journal of Magnesium and Alloys, Volume 8, Issue 1, 2020, Pages 1–41, ISSN 2213–9567, https://doi.org/10.1016/j.jma.2020.02.003 . Additional Declarations No competing interests reported. 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. 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1","display":"","copyAsset":false,"role":"figure","size":2067927,"visible":true,"origin":"","legend":"\u003cp\u003eOptical micrographs of stir cast alloy a) As cast , b) Rolled at 100°C, c) Rolled at 200°C, d) Rolled at 300°C, e) Rolled at 400°C.\u003c/p\u003e","description":"","filename":"floatimage1.jpeg","url":"https://assets-eu.researchsquare.com/files/rs-7619268/v1/b4ae26e3cf39ace93c4d013a.jpeg"},{"id":94546744,"identity":"abdd6aa2-4d13-4b44-8ace-a11f1947a6c0","added_by":"auto","created_at":"2025-10-28 17:40:45","extension":"jpeg","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":3441952,"visible":true,"origin":"","legend":"\u003cp\u003eThermal mapping of micrographs of modified AZ61 alloy under various conditions a) As cast , b) Rolled at 100°C, c) Rolled at 200°C, d) Rolled at 300°C, e) Rolled at 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7","display":"","copyAsset":false,"role":"figure","size":1118972,"visible":true,"origin":"","legend":"\u003cp\u003eTemperature field for dendrite formation of modified AZ 61 alloy under as cast conditions, a) Dendrite formation with solidification temperature field, b) Temperature distribution along dendrite boundaries\u003c/p\u003e","description":"","filename":"Onlinefloatimage7.png","url":"https://assets-eu.researchsquare.com/files/rs-7619268/v1/e11fa8e1e146344fc5660c21.png"},{"id":94546732,"identity":"2c016773-ba9b-467f-afde-8d434f997bd2","added_by":"auto","created_at":"2025-10-28 17:40:34","extension":"jpeg","order_by":8,"title":"Figure 8","display":"","copyAsset":false,"role":"figure","size":2454258,"visible":true,"origin":"","legend":"\u003cp\u003eSANS intensity (log scale) patterns on the 2D detector for the modified AZ 61 alloy under various condition, a) As cast , b) Rolled at 100°C, c) Rolled at 200°C, d) Rolled at 300°C, e) Rolled at 400°C\u003c/p\u003e","description":"","filename":"floatimage8.jpeg","url":"https://assets-eu.researchsquare.com/files/rs-7619268/v1/93591ba045ce3cc114090832.jpeg"},{"id":94546883,"identity":"bf3a5023-564a-48e9-adfe-97981a0d231b","added_by":"auto","created_at":"2025-10-28 17:41:22","extension":"jpeg","order_by":9,"title":"Figure 9","display":"","copyAsset":false,"role":"figure","size":219159,"visible":true,"origin":"","legend":"\u003cp\u003eX-ray diffraction (XRD) result of stir cast AZ61 alloy, a) Rolled at 200 °C, b) As cast condition\u003c/p\u003e","description":"","filename":"floatimage9.jpeg","url":"https://assets-eu.researchsquare.com/files/rs-7619268/v1/359b8ee9ebaf983012db99b0.jpeg"},{"id":94547001,"identity":"8aabf1da-2cd3-4e41-9b67-5a524eeb55be","added_by":"auto","created_at":"2025-10-28 17:41:43","extension":"png","order_by":10,"title":"Figure 10","display":"","copyAsset":false,"role":"figure","size":93011,"visible":true,"origin":"","legend":"\u003cp\u003eDSC of stir cast AZ61 alloy [heating run @ 10\u003csup\u003e0\u003c/sup\u003eK/min]. (a) DSC heating curve (b) DSC peak occurring at 83.5 \u003csup\u003e0\u003c/sup\u003eC (c) Arrhenius plot as per Nagasaki-Maesono relation\u003c/p\u003e","description":"","filename":"floatimage10.png","url":"https://assets-eu.researchsquare.com/files/rs-7619268/v1/fd17484aa2ef1053f244bae4.png"},{"id":97141286,"identity":"b002f6bb-bf4e-453e-a1f2-f253f7aae37b","added_by":"auto","created_at":"2025-12-01 10:06:32","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":15155392,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-7619268/v1/bd6707d5-71b3-4b6c-a7a1-5a601aa2cbb5.pdf"}],"financialInterests":"No competing interests reported.","formattedTitle":"Multi Scale Analysis of Modified AZ61 Alloy Evolution of β-Mg17Al12 Phase and Structure–Property Correlation","fulltext":[{"header":"1. Introduction","content":"\u003cp\u003eThe use of magnesium alloys is becoming increasingly prevalent among manufacturers as a means of meeting the ever-growing demand for lightweight applications. Mg alloys, however, exhibit minimal plastic deformation by dislocation due to the formation of a strong basal texture [\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e]. This occurs because there are no slip systems present, and the basal texture is robust. Mg also demonstrates isotropy in movement. Various approaches have been employed to improve the ductility of magnesium alloys [\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e]. These methods include raising the temperature, refining the grain, altering the mechanical behavior, and modifying the texture. Among the different types of magnesium alloys, Mg-Al is the most common. They are part of the wrought magnesium alloy family and are relatively inexpensive, offering intermediate strengths, acceptable ductility, and reasonable corrosion resistance. The flexibility of certain AZ, AM, and AE magnesium alloys is particularly noteworthy. For example, the AZ31 and AZ61 alloys belong to the AZ family of magnesium alloys and are characterized by their exceptional flexibility, strength, and resistance to corrosion [\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e].\u003c/p\u003e\u003cp\u003eMost magnesium-aluminium alloys have an aluminium content of less than 10% by weight. The presence of the β-phase, namely β-Mg\u003csub\u003e17\u003c/sub\u003eAl\u003csub\u003e12\u003c/sub\u003e, in the microstructure of the magnesium alloy cast at a moderate cooling rate is caused by nonequilibrium solidification. The proportion of the β-phase increases in magnesium-aluminium alloys as the amount of aluminium in the alloy is raised [\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e]. Micro alloying elements including Ti, Bi, Sb, Sn, and Sr, together with rare earth (RE) elements, have the potential to change the morphology of the β-Mg\u003csub\u003e17\u003c/sub\u003eAl\u003csub\u003e12\u003c/sub\u003e phase. These components have the ability to alter the amount, dimensions, dispersion, and direction of the β-phase [\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e]. Additionally, the mechanical properties of the material are enhanced as a result of micro alloying since it refines the α-Mg grains. The micro alloying elements hinder the growth of the grains and β-Mg\u003csub\u003e17\u003c/sub\u003eAl\u003csub\u003e12\u003c/sub\u003e phase because they are concentrated at the solid-liquid interfaces during the solidification process [\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e]. Consequently, the α-Mg matrix's grains undergo refining. The second phase can be formed when magnesium is combined with specific alloying components. The overall quantity of β-Mg\u003csub\u003e17\u003c/sub\u003eAl\u003csub\u003e12\u003c/sub\u003e is reduced and the dispersion of this phase is improved as a consequence of this rivalry, which decreases the efficiency of the combination of the Mg and Al elements. Al\u003csub\u003e2\u003c/sub\u003eCa, Mg\u003csub\u003e3\u003c/sub\u003eBi\u003csub\u003e2,\u003c/sub\u003e Mg\u003csub\u003e3\u003c/sub\u003eSb\u003csub\u003e2\u003c/sub\u003e and A1-RE are examples of the low-content second phases in the alloy that can be seen as needles or particles [\u003cspan additionalcitationids=\"CR8 CR9\" citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e].\u003c/p\u003e\u003cp\u003eBoth researchers and industry professionals are interested in re-refining magnesium alloy grains due to the advantages offered by a more refined microstructure. Numerous methods exist to control the size of metal and alloy grains during solidification. Increasing the cooling rate during solidification is the primary approach [\u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e]. However, this process is incompatible with most industrial castings, especially those with thicker walls. Alternatively, alloying elements can be introduced during the melting process. The limited solubility of these elements in solidified grains leads to their entrapment at the solid/liquid boundary. The formation of nucleated grains is hindered when the liquid is rich in solute atoms [\u003cspan additionalcitationids=\"CR13\" citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e]. Different alloying elements have varying abilities to restrict grain growth. To predict the characteristics and performance of the final product, a thorough examination of the material's microstructure during production and any subsequent heat treatments is essential. Controlling the microstructure requires familiarity with its constituent phases and their macroscale effects based on composition, form, and specific qualities. Optimizing material properties for a particular application depends on this knowledge, which is crucial across various production processes [\u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e15\u003c/span\u003e].\u003c/p\u003e\u003cp\u003eA detailed understanding of digital microstructure, which involves phenomena from visualization and characterization of microstructures to mechanical analysis based on different grain or phase structures, is important in the context of materials science, as digital microstructure contains a wealth of relevant digital data that can be used in numerous practical applications [\u003cspan additionalcitationids=\"CR17\" citationid=\"CR16\" class=\"CitationRef\"\u003e16\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR18\" class=\"CitationRef\"\u003e18\u003c/span\u003e]. So far, significant attention and effort have been dedicated to the development of tools and procedures that enable users to fully utilize digital microstructures (DMs) in their development workflow. Digital microstructure has been employed to predict or analyze a wide range of microstructure-sensitive properties, including mechanical characteristics such as strength and ductility, thermal properties, corrosion resistance, recrystallization, and phase transformation [\u003cspan citationid=\"CR19\" class=\"CitationRef\"\u003e19\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR20\" class=\"CitationRef\"\u003e20\u003c/span\u003e].\u003c/p\u003e\u003cp\u003eAZ 61 wrought magnesium alloys exhibit poor formability and low ductility at room temperature due to their hexagonal close-packed (hcp) structure. The process of grain refinement for wrought magnesium alloys designated as AZ 61 is not yet fully understood. Therefore, it is essential to investigate the effects of smaller additions of grain refining materials and ultimately determine the optimal composition for achieving the highest possible level of grain refinement. An enhancement in the grain refinement method is necessary to produce an AZ 61 magnesium alloy with exceptional mechanical properties. Finding a solution to improve the ductility and strength of AZ 61 alloys through the stir-casting process by refining grains is challenging.\u003c/p\u003e\u003cp\u003eUtilizing novel image analysis and processing techniques, this work aims to investigate the microstructure of a modified AZ61 alloy with the goal of leveraging the microstructural features and mechanical strength, as well as their close relationship with the microstructure and phase. Previous literature suggests that this processing method and composition development can significantly enhance the properties of these alloys. The enhancements arise from fine-tuning the microstructure and age-hardening it with small alloying elements. This study is based on the premise that creating an AZ61-based alloy with improved properties can be achieved through a combined approach involving grain refinement and precipitation hardening. To this end, small amounts of Sc and Ca were added to traditional AZ61 to form new alloys. Scandium is used for its capacity to enhance the cast structure by inhibiting dendrite growth and to facilitate age-hardening through the formation of Al3Sc precipitates. Conversely, calcium aids in the development of Mg\u003csub\u003e2\u003c/sub\u003eCa and Al\u003csub\u003e2\u003c/sub\u003eCa phases, which are recognized to promote age-hardening. Such modifications are made during the stir casting process, which enables structural refinement by minimizing diffusion lengths for alloying species to optimize age-hardening. This research addresses the limitations of existing traditional methods of microstructural analysis. Most commercial software are not sufficiently effective in recognizing and quantifying microstructure. To resolve this issue, we employ an automated image processing approach capable of detecting grain sizes, phase proportions, and interfacial characteristics. These analyses encompass the kinetics of phase transformation, as well as the phase-property relationship, allowing for a comprehensive analysis of the performance of the modified AZ61 alloy.\u003c/p\u003e"},{"header":"2. Experimental Procedure","content":"\u003cp\u003eThe elements contained in AZ61 alloys and minor additions of elements during casting help characterize the advantages of stir casting. The nominal composition of the modified alloy was Mg-6 Al-1 Zn-0.5 Mn-0.5 Ca-0.2 Sc. A chemical balance was used to measure the weight of dried ingredients. Melting was conducted in a resistive heating pot furnace equipped with a stirrer. Magnesium and aluminum were poured into the melting pot once the temperature reached 750\u0026deg;C, followed by zinc, manganese, and calcium, before finally adding scandium. For each melt, 10 wt. % more elements than theoretically necessary were introduced to account for oxidation losses. Stirring at 600 rpm was applied for 15 minutes to create a homogeneous melt before pouring it into preheated metal molds (200 mm \u0026times; 20 mm \u0026times; 20 mm) at 200\u0026deg;C to minimize the chilling effect. A multi-scale experimental study was conducted to investigate the effect of various thermal/mechanical approaches on the phase evolution analysis of the AZ61 magnesium alloy (formability aspects, β-Mg\u003csub\u003e17\u003c/sub\u003eAl\u003csub\u003e12\u003c/sub\u003e phases, dendritic morphology, and microstructural aspects) to obtain the inherent structural characteristics. Casting the alloy samples into the desired molds, followed by rolling to a thickness of 0.5 mm at 100\u0026deg;C, 200\u0026deg;C, 300\u0026deg;C, and 400\u0026deg;C resulted in differing degrees of alignment of the β-Mg\u003csub\u003e17\u003c/sub\u003eAl\u003csub\u003e12\u003c/sub\u003e phase. Mechanical grinding of the samples in stages up to 2500 emery paper is carried out under continuous water flow to remove ground debris and for sample cooling; this is thereafter followed by optical metallographic analysis. The samples are then polished on cloth with diamond suspension from 9 \u0026micro;m to 1 \u0026micro;m and with alumina suspension compound of 0.5 \u0026micro;m (successively finer), and cleaned in an ethanol bath and sonicated for about 10 minutes to remove loose particles from the surfaces following grinding. After sonication-assisted drying in ethanol, they are etched with a solution of (25 ml ethanol\u0026thinsp;+\u0026thinsp;5 ml acetic acid\u0026thinsp;+\u0026thinsp;1.5 gm picric acid\u0026thinsp;+\u0026thinsp;10 ml distilled water). The etching is performed for about 20 seconds, and the etching time is also optimized with the samples if needed. A post-etch water rinse is applied to the above samples. Optical microscopy and Small Angle Neutron Scattering (SANS) are used to shed light on nanoscale structural alterations of the samples. Post-processing was performed on the 2D view intensity profile before the beam-based therapy, analyzing the texture/morphology evolution by extracting log-scaled intensity patterns from images and diagrams. Thermal maps from 550\u0026deg;C to 100\u0026deg;C were created to study the solidification and thermal gradient, which are key for dendrite growth and solute segregation studies. Secondary phase evolution and grain refinement were also confirmed through computational analyses of solidification fields and boundary temperature distributions.\u003c/p\u003e"},{"header":"3. Results and Discussion","content":"\u003cdiv id=\"Sec4\" class=\"Section2\"\u003e\u003ch2\u003e3.1. Microstructure examination of modified AZ 61 alloy\u003c/h2\u003e\u003cp\u003eFigure \u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003ea illustrates the characteristic cellular dendritic micromorphology of the as-cast AZ61 alloy microstructure, which is unique to the stir-cast modified AZ61 alloy. This framework develops from constitutional supersaturation during the solidification process in high-speed extrusion that suppresses dendrite growth. The as-cast samples display two primary phases: the α-Mg matrix and the β- Mg₁₇Al₁₂ phase situated at the grain boundaries. The microstructure is refined through the rapid stirring of alloy constituents during casting, which imparts mechanical strength to the cooled metal. After rolling at 100\u0026deg;C, Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003eb reflects the slightly recrystallized grain size and partially equiaxed structure, while Sc can enhance mechanical properties by modifying the Mg₁₇Al₁₂ phase. Improved mechanical properties, second-phase dispersion, and anodized surface uniformity are characteristic features of the refined equiaxed grain structure. It is known that rolling at 200\u0026deg;C leads to grain refinement; Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003ec showcases this phenomenon, followed by peak hardness due to an increased volume fraction of the second phase. The in situ formed dense plate-like Mg₂Ca phase during casting significantly enhances hardness, and it has been previously confirmed by X-ray diffraction that the presence of 0.5 wt% Ca results in considerable grain refinement. The increased microhardness of Mg₂Ca phases at 200\u0026deg;C results in improved rolling properties. Figure\u0026nbsp;\u003cspan refid=\"Fig3\" class=\"InternalRef\"\u003e3\u003c/span\u003e, Processing / Microstructure / Hardness relationship: as the solute supersaturated solid solutions formed at short aging times decompose, a maximum in Vickers hardness occurs at 200\u0026deg;C. The grain size decreases with rolling at 300\u0026deg;C and 400\u0026deg;C; however, excessive softening at higher temperatures leads to a further decrease in hardness and yield strength, emphasizing the importance of temperature in optimizing properties (Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003ed and \u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003ee).\u003c/p\u003e\u003cp\u003e\u003c/p\u003e\u003c/div\u003e\u003cdiv id=\"Sec5\" class=\"Section2\"\u003e\u003ch2\u003e3.2. Thermal mapping with temperature gradient of modified AZ61 alloy\u003c/h2\u003e\u003cp\u003eThe thermal maps of AZ61 alloy at various temperatures reveal the complex evolution of its microstructure through the detection of its primary and secondary phases, grain boundaries, and grain refinement. These alterations in microscale structure significantly impact the properties of the alloy at the material size level, including corrosion resistance, thermal stability, and deformation behavior. In the Cast Condition (Fig.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003eb), the thermal map shows a heterogeneous microstructure with coarse α-Mg grains coarsely separated by intermetallic β-Mg\u003csub\u003e17\u003c/sub\u003eAl\u003csub\u003e12\u003c/sub\u003e phases at the grain boundaries. The marked tendency toward the brittle β-phase indicates a susceptibility to cracking upon deformation and a tendency for lower corrosion resistance due to galvanic coupling with the α\u0026thinsp;\u0026minus;\u0026thinsp;Mg matrix. This is caused by the solidification process, which encourages coarse grain coarsening and β-phase particle segregation. Rolled at 100\u0026deg;C (Fig.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003eb), the material displays coarse grain structures with some grain boundary alignment due to mechanical rolling, as suggested in the map. The β-Mg\u003csub\u003e17\u003c/sub\u003eAl\u003csub\u003e12\u003c/sub\u003e phases remain stable, and only their fragmentation begins, which slightly decreases the microstructural heterogeneity. This is influenced by the persistence of coarse grains and grain boundary phases in thermal stability, thus hindering improvements in isotropy. Rolled at 200\u0026deg;C (Fig.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003ec), dynamic recrystallization is observed in this micrograph, appearing as equiaxial grains that form uniformly. These refined grain boundaries and dispersed β-phase contribute to the improved stability of the phases and inhibited grain growth. This small grain structure enhances resistance to thermomechanical processes through reinforcement against creasing and improved homogeneity. Rolled at 300\u0026deg;C (Fig.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003ed), the grain structure becomes finer, with significant dissolution of the β-phase. This improvement enhances thermal stability and reduces the risk of intergranular corrosion by ensuring consistent grain boundaries and phase distribution. Rolled at 400\u0026deg;C (Fig.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003ee), thermal mapping reveals widespread grain boundary stabilization and near-total β-Mg\u003csub\u003e17\u003c/sub\u003eAl\u003csub\u003e12\u003c/sub\u003e dissolution. The fine grain structure promotes a more homogenous composition, improves oxidation resistance, and enhances thermal stability while reducing stress concentrations from phases. The phase and grain boundary analysis of the AZ61 alloy aids in understanding its structural integrity and stability under specific conditions. The knowledge of these changes can be leveraged to maximize the potential usefulness of the materials in applications where thermal stability, corrosion resistance, and processability are essential.\u003c/p\u003e\u003cp\u003e\u003c/p\u003e\u003c/div\u003e\u003cdiv id=\"Sec6\" class=\"Section2\"\u003e\u003ch2\u003e3.3. Histogram plot of modified AZ61 alloy\u003c/h2\u003e\u003cp\u003eFrom the results, it is determined that the histogram plot can provide unique insights into the microstructure of the AZ61 alloy that are very difficult to observe with a conventional microscope. Histograms of pixel intensity distributions (Fig.\u0026nbsp;\u003cspan refid=\"Fig3\" class=\"InternalRef\"\u003e3\u003c/span\u003e) were well correlated with the microstructure tonal variation data, showing significant differences in shapes, sizes, and percentage distributions. The x-axis represents pixel intensity (0-255), while the y-axis represents pixel number, with different patterns reflecting the alloy's heterogeneity. In (Fig.\u0026nbsp;\u003cspan refid=\"Fig3\" class=\"InternalRef\"\u003e3\u003c/span\u003ea), a mean intensity of 147.875 and a standard deviation of 72.188 reveal a wide intensity range, indicating a complex microstructure characterized by a mixture of phases. A broad distribution suggests a mixture of α-Mg and β-Mg\u003csub\u003e17\u003c/sub\u003eAl\u003csub\u003e12\u003c/sub\u003e phases with varying grain characteristics, which are associated with improved strength through grain boundary precipitation hardening. Conversely, (Fig.\u0026nbsp;\u003cspan refid=\"Fig3\" class=\"InternalRef\"\u003e3\u003c/span\u003eb) has an average intensity of 150.037 and a lower standard deviation of 53.353 compared to (Fig.\u0026nbsp;\u003cspan refid=\"Fig3\" class=\"InternalRef\"\u003e3\u003c/span\u003ea), implying a more homogeneous microstructure with uniformly distributed secondary phases and grain size. This ordering results in enhanced yield strength and mechanical properties. Histograms in (Fig.\u0026nbsp;\u003cspan refid=\"Fig3\" class=\"InternalRef\"\u003e3\u003c/span\u003ec-e) represent narrower intensity distributions with mean intensities ranging from 85.504 to 101.226 and standard deviations from 20.111 to 27.717. These indicate a similar grain size and a lower amount of β-Mg\u003csub\u003e17\u003c/sub\u003eAl\u003csub\u003e12\u003c/sub\u003e phase, leading to reduced strength and higher ductility and toughness. The analysis highlights that adjustments to the processing of microstructures can optimize the mechanical properties of the AZ61 alloy, effectively balancing strength and ductility. Narrow and wide intensity distributions correlate with uniform and complex grain structures, respectively.\u003c/p\u003e\u003cp\u003e\u003c/p\u003e\u003c/div\u003e\u003cdiv id=\"Sec7\" class=\"Section2\"\u003e\u003ch2\u003e3.4. Surface Profile of modified AZ61 alloy\u003c/h2\u003e\u003cp\u003eThe simulated grain-refining microstructures also directly reflect the distribution of the secondary phase and the surface hardness in AZ61 magnesium alloy (see Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003e to \u003cspan refid=\"Fig3\" class=\"InternalRef\"\u003e3\u003c/span\u003e). The analysis of Fig.\u0026nbsp;\u003cspan refid=\"Fig4\" class=\"InternalRef\"\u003e4\u003c/span\u003ea and Fig.\u0026nbsp;\u003cspan refid=\"Fig4\" class=\"InternalRef\"\u003e4\u003c/span\u003eb illustrates the features of the alloy through polyhedra based on the distance in pixels and volume change across the alloy's composition. The variations in gray values indicate inconsistencies in surface hardness, possibly due to the non-uniform distribution of alloy constituents, diversity in microstructure, and processing methods, such as heat treatment. The peaks in these graphs represent areas of sheen that the coarser crystallization of lower hardness, revealed in the troughs, cannot maintain. Grain refinement can significantly improve the mechanical properties of magnesium alloys. As shown in Fig.\u0026nbsp;\u003cspan refid=\"Fig4\" class=\"InternalRef\"\u003e4\u003c/span\u003ec and Fig.\u0026nbsp;\u003cspan refid=\"Fig4\" class=\"InternalRef\"\u003e4\u003c/span\u003ed, the finely processed grains diminish the characteristically needle-like structures of the magnesium grains, leading to a refined structure that enhances hardness and strength through the Hall-Petch effect, whereby smaller grains inhibit dislocation motion. However, the weakening of the alloy increases with the formation of relevant grain boundary structures; secondary phases like β-Mg\u003csub\u003e17\u003c/sub\u003eAl\u003csub\u003e12\u003c/sub\u003e often emerge throughout the phase network at the grain boundary, allowing increased dislocation movement that creates additional slip lines, as suggested by the higher gray values shown in Fig.\u0026nbsp;\u003cspan refid=\"Fig4\" class=\"InternalRef\"\u003e4\u003c/span\u003ee. These phases also enhance wear resistance and mechanical strength. Poor microstructure uniformity and hardness can be observed in cast magnesium alloys, underscoring the importance of optimized processing conditions to promote uniformity, refined microstructures, and performance.\u003c/p\u003e\u003cp\u003e\u003c/p\u003e\u003c/div\u003e\u003cdiv id=\"Sec8\" class=\"Section2\"\u003e\u003ch2\u003e3.5. Analysis of Grain size distribution of optical micrograph of modified stir AZ61 alloy\u003c/h2\u003e\u003cp\u003eIt illustrates the variation in grain size of stir-cast AZ61 alloy at various aging temperatures. Figure\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003e(b-e): Schematic representation of the measured and obtained results in Fig.\u0026nbsp;\u003cspan refid=\"Fig5\" class=\"InternalRef\"\u003e5\u003c/span\u003e. In contrast, the grain size in Fig.\u0026nbsp;\u003cspan refid=\"Fig5\" class=\"InternalRef\"\u003e5\u003c/span\u003ea ranged from approximately 40 \u0026micro;m to 160 \u0026micro;m, with most grains between 60 and 100 \u0026micro;m; this broader distribution indicates a coarser microstructure expected to exhibit lower hardness due to reduced grain boundary density. The diminished hardness is attributed to the uneven distribution of grain sizes, likely resulting from insufficient grain refinement. Microstructure sizes are generally smaller than those observed in as-cast metal, as seen in Fig.\u0026nbsp;\u003cspan refid=\"Fig5\" class=\"InternalRef\"\u003e5\u003c/span\u003eb, which shows the grain size primarily ranging between 8 and 16 \u0026micro;m, indicating that grain refinement, microstructure homogenization, and dissolution of secondary phases occur during heat treatment. Numerous studies have demonstrated that such processes lead to superior mechanical properties; for instance, hardness is expressed by the Hall-Petch relationship, where a higher density of finer grains hinders dislocation movement, resulting in a stronger material. As shown in Fig.\u0026nbsp;\u003cspan refid=\"Fig5\" class=\"InternalRef\"\u003e5\u003c/span\u003ec and \u003cspan refid=\"Fig5\" class=\"InternalRef\"\u003e5\u003c/span\u003ed, the grain size distribution is relatively uniform, mostly within the 4 to 8 \u0026micro;m range; this may be due to effective heat treatment and alloying with elements like Al or Ca, which significantly assist in refining the microstructure. The resulting small-grained equiaxed structure enhances hardness, ductility, and overall wear resistance. Another important strengthening phase is the well-known Mg17Al12 phase located at the grain boundaries, which greatly enhances resistance to deformation by impeding dislocation movement. Consequently, the development of finer grain structures leads to increased hardness, tensile strength, and improved mechanical properties of the AZ61 alloy.\u003c/p\u003e\u003cp\u003e\u003c/p\u003e\u003c/div\u003e\u003cdiv id=\"Sec9\" class=\"Section2\"\u003e\u003ch2\u003e3.6. 3D feature maps of an optical micrograph of modified stir AZ61 alloy\u003c/h2\u003e\u003cp\u003eAnalysis insights for 3D feature maps of modified AZ61 magnesium alloy under different conditions. The maps show the evolution of secondary phases and microstructural features during thermal and mechanical treatments of the alloy. As Cast Condition (Fig.\u0026nbsp;\u003cspan refid=\"Fig6\" class=\"InternalRef\"\u003e6\u003c/span\u003ea), feature map shows high randomness, suggestive of a heterogeneous nature in microstructure with considerable porosity and coarse secondary phase β-Mg\u003csub\u003e17\u003c/sub\u003eAl\u003csub\u003e12\u003c/sub\u003e, Large grains and inhomogeneous precipitation are structure characteristics that are common with as cast AZ61 alloys. This arrangement, in turn, affects properties such as low ductility and moderate strength. Rolled at 100\u0026deg;C (Fig.\u0026nbsp;\u003cspan refid=\"Fig6\" class=\"InternalRef\"\u003e6\u003c/span\u003eb), the feature map exhibits a decrease in the amplitude of the peaks indicating enhanced homogeneity and partial recrystallization. This leads to the formation of fine secondary phases along the rolling directions which increases the strength, however, not very much improves the ductility. Rolled at 200\u0026deg;C (Fig.\u0026nbsp;\u003cspan refid=\"Fig6\" class=\"InternalRef\"\u003e6\u003c/span\u003ec), the increased rolling temperature manifests in the further refined microstructure and dispersion of the secondary phase. Some dissolution of the secondary β-Mg\u003csub\u003e17\u003c/sub\u003eAl\u003csub\u003e12\u003c/sub\u003e phase takes place which also helps in grain boundary pinning. These conditions offer optimized mechanical properties combining increased ductility with strength. Rolled at 300\u0026deg;C (Fig.\u0026nbsp;\u003cspan refid=\"Fig6\" class=\"InternalRef\"\u003e6\u003c/span\u003ed), the feature map smooths further and illustrates extensive grain refinement and recrystallization. Destruction of second-phase precipitates causing excellent ductility with retained strength. Rolled at 400\u0026deg;C (Fig.\u0026nbsp;\u003cspan refid=\"Fig6\" class=\"InternalRef\"\u003e6\u003c/span\u003ee): The feature map is consistent, indicating that the observed changes are due to extending grain growth and a decrease in dislocation density. There are not many secondary phases left offering good ductility but low yield strength. This data is critical for predicting and optimizing material properties like strength, ductility, or thermal stability for AZ61, offering industry-customized processing within the automotive and aerospace domains.\u003c/p\u003e\u003cp\u003e\u003c/p\u003e\u003c/div\u003e\u003cdiv id=\"Sec10\" class=\"Section2\"\u003e\u003ch2\u003e3.7. Solidification of alloy and dendrite formation analysis of modified AZ61 alloy in cast condition\u003c/h2\u003e\u003cp\u003eFigure \u003cspan refid=\"Fig7\" class=\"InternalRef\"\u003e7\u003c/span\u003ea shows the dendrite formation and solidification temperature field, which can help researchers analyze the complex thermodynamic and kinetic environment during the solidification of AZ61 magnesium alloy. The temperature gradient, observed from 550\u0026deg;C (yellow region) to below 100\u0026deg;C (dark red region) in the direction of heat extraction, substantiates the previously noted effect on dendritic nucleation and growth. This gradient also suggests a competition between thermal and constitutional undercooling that dictates the stability of dendritic growth. Above collectors, the dendrites are intricate, indicating the functionality of columnar growth as the high-temperature gradients in the upper regions favor directional solidification.\u003c/p\u003e\u003cp\u003eHowever, with decreasing temperature in the lower zones the effect of thermal gradients and constitutional undercooling leads to epitaxial growth changing to a more equiaxed dendritic structure. This transition zone is where mechanical integrity of the material is altered since defects can occur in that zone if poorly controlled during solidification. It can be observed how solute elements (for example, aluminium and zinc) are segregated into the interdendritic regions during solidification. These factors control the solidification path such that they decrease the melting point locally and leave some residual liquid pockets between the dendritic arms. Last to solidify are such pockets, which form β-Mg\u003csub\u003e17\u003c/sub\u003eAl\u003csub\u003e12\u003c/sub\u003e phases that segregate along grain boundaries. These phases can serve as sites of crack initiation under mechanical loading and also increase susceptibility to localized corrosion, particularly in chloride-rich environments.\u003c/p\u003e\u003cp\u003eThe temperature map highlights areas with higher gradients that contribute to finer dendritic arm spacing (secondary arm spacing, SAS). It has also been demonstrated that finer SAS results in improved mechanical isotropy, reduced porosity, and enhanced phase homogeneity during processing. However, dendrites with a coarser structure are likely to form in areas of low thermal gradient, leading to anisotropic characteristics and consequently lower ductility and fatigue resistance. The various temperature zones provide valuable insight into the cooling curve of the alloy and the time required for solidification in each region. This results in rapid nucleation in the upper regions, where cooling is more rapid and dendritic growth is limited, while slower cooling in the lower regions encourages the formation of well-structured larger dendritic arms. This principle can be applied in casting process design, such as strategically positioning chillers or heat sources in different sections of the mold, to manage the cooling rate and achieve desired microstructural features. This signifies the necessity for controlled thermal gradients and cooling rates when casting AZ61 alloy. Utilizing advanced data processing techniques, such as directional solidification or controlled cooling methods via computational simulations, allows for optimization of the microstructure. This leads to fewer casting defects, e.g., segregation and porosity, which enhances the corrosion resistance, thermal stability, and mechanical properties of the material. Dendritic growth and secondary phase formation are meticulously controlled, enabling customized property enhancement and reliability under severe operational conditions.\u003c/p\u003e\u003cp\u003e(Fig.\u0026nbsp;\u003cspan refid=\"Fig7\" class=\"InternalRef\"\u003e7\u003c/span\u003eb) shows an internal cross section of dendrite tip length at an equiaxed temperature within the modified AZ61 alloy in its as-cast condition. Note that temperature values vary between 600\u0026deg;C and below 100\u0026deg;C, indicating the non-linear cooling that occurs during casting. Drastic temperature drops are observed across specific boundary indices, highlighting regions with high thermal gradients that are crucial for dendrite nucleation and growth. The changes in the cooling curve reflect the local solidification rate, which affects the secondary arm spacing (SAS) of the dendrites. Finer dendritic structures form in regions with faster cooling, while coarser dendritic arms are found in broader boundary regions with slower cooling, resulting from variations in SAS. The temperature across the boundary is non-uniformly distributed, which is particularly significant as it relates directly to micro segregation. Alloying elements such as aluminum and zinc are expelled from the primary α-Mg phase, becoming concentrated in the interdendritic regions, which can also facilitate the formation of local secondary β-Mg\u003csub\u003e17\u003c/sub\u003eAl\u003csub\u003e12\u003c/sub\u003e phases. Such segregation negatively impacts the structural homogeneity of the metal, making it more susceptible to stress corrosion cracking and galvanic corrosion. Additionally, steep temperature gradients influence dendrite morphologies.\u003c/p\u003e\u003cp\u003eColumnar dendritic growth is favored in higher gradients while equiaxed structures occur in lower gradients. This structural variation contributes to the mechanical isotropy and thermal stability of the alloy. Therefore, this study demonstrates that cooling rates in the casting process must be controlled. This notably aids in mitigating segregation, generating dendritic structures with refined morphology, and consequently enhancing the overall mechanical and corrosion-resistant characteristics of the AZ61 alloy. Such information is valuable for optimizing casting conditions in industry. The current analysis can assist in designing magnesium alloys with improved performance for significant applications, such as automotive and aerospace components, thereby integrating experimental observations with computational modeling.\u003c/p\u003e\u003cp\u003e\u003c/p\u003e\u003c/div\u003e\u003cdiv id=\"Sec11\" class=\"Section2\"\u003e\u003ch2\u003e3.8. Small- angle neutron scattering of modified AZ61 alloy under various conditions\u003c/h2\u003e\u003cp\u003eA detailed account of the nanoscale structural evolution, phase orientation, and geometry of AZ61 alloy under various dispersive mechanical and thermal conditions was examined through Small-Angle Neutron Scattering (SANS) intensity patterns. This analysis is fundamental to understanding the dynamic evolution of the microstructural features and their impact on the mechanical and physical properties of the alloy. In the As-Cast Condition (Fig.\u0026nbsp;\u003cspan refid=\"Fig8\" class=\"InternalRef\"\u003e8\u003c/span\u003ea), the as-cast SANS pattern shows a broad spot around a distinct peak center, suggesting a large secondary phase, β-Mg\u003csub\u003e17\u003c/sub\u003eAl\u003csub\u003e12\u003c/sub\u003e, distributed over irregular spacing. The large diffuse halo indicates substantial heterogeneity and an absence of crystalline orientation. The lack of strong anisotropic scattering features means there is little texturing in the as-cast state. Resulting from rapid solidification and thermal gradients, solute segregation occurs at the grain boundaries. Therefore, from the observed microstructural geometry, the phase continuity is poor, and distortion leads to rough stress distribution, which is crucial for fracture toughness. When rolled at 100\u0026deg;C (Fig.\u0026nbsp;\u003cspan refid=\"Fig8\" class=\"InternalRef\"\u003e8\u003c/span\u003eb), the central intensity decreases due to the partial fragmentation of secondary phases. Texture evolution of the grains and sub-grains, with a starting alignment, is revealed by the scattering pattern. At this temperature, mechanical deformation effectively breaks up β-Mg\u003csub\u003e17\u003c/sub\u003eAl\u003csub\u003e12\u003c/sub\u003e phase clusters, improving the uniformity of phase distribution. However, the lower deformation temperature limits complete recrystallization, and some microstructural anisotropy remains. When rolled at 200\u0026deg;C (Fig.\u0026nbsp;\u003cspan refid=\"Fig8\" class=\"InternalRef\"\u003e8\u003c/span\u003ec), a cross-like feature emerges in the SANS intensity map, indicating alignment of crystalline structures along the rolling direction. This phenomenon is evidence of dynamic recrystallization, involving the refinement of sub-grains, followed by the dissolution of secondary phases into the matrix, such as β-Mg\u003csub\u003e17\u003c/sub\u003eAl\u003csub\u003e12\u003c/sub\u003e. The nanoscale alignment indicates a better compromise between strength and ductility, as well as reduced stress concentrations in smaller secondary phases. This condition also promotes grain boundary strengthening, improving the alloy\u0026rsquo;s overall protection against intergranular corrosion. When rolled at 300\u0026deg;C (Fig.\u0026nbsp;\u003cspan refid=\"Fig8\" class=\"InternalRef\"\u003e8\u003c/span\u003ed), the scattering pattern widens at 300\u0026deg;C, and the intensity distribution becomes weak and diffuse, suggesting that the grain structure is significantly refined and the β-phase extensively dissolved. An isotropically buffered nanostructure resulting from full recrystallization and grain rotation leads to a uniform scattering distribution. The material geometry shifts to equiaxed grains, aiding in resisting localized corrosion and decreasing flow-induced anisotropy. This stage reveals a fine microstructure, indicating increased thermal stability. When rolled at 400\u0026deg;C (Fig.\u0026nbsp;\u003cspan refid=\"Fig8\" class=\"InternalRef\"\u003e8\u003c/span\u003ee), the SANS pattern exhibits lower intensity and highly symmetric scattering, reflecting full recrystallization and a minimal amount of residual second phases. Grains are fine and equiaxed under these conditions, resulting in a highly homogeneous structure that decreases internal stresses and increases ductility. However, such significant grain growth and near-complete dissolution of strengthening phases may decrease the alloy\u0026rsquo;s tensile strength. The evolution of the SANS patterns provides key insights into how the distribution of the secondary phase, crystallographic texture, and nanoscale geometry interact. The decay of anisotropic trapped features and the increase in the width of the scattering halo clearly indicate the disappearance of the β-Mg\u003csub\u003e17\u003c/sub\u003eAl\u003csub\u003e12\u003c/sub\u003e phase and the evolution from a textured to a near-isotropic microstructure. The examination further illustrates the significant impact of rolling temperature on dynamic recrystallization, resulting in the formation of finer grains and increased uniformity of the phases at elevated temperatures. In this study, SANS is employed to obtain information that would be challenging to achieve using traditional microscopy; the combination of SANS and other techniques ensures that the structure can be analyzed and thoroughly discussed in more detail. This analysis also helps optimize nanoscale features to improve mechanical and thermal properties, such as resistance to fatigue, corrosion, and thermal stability, by addressing processing conditions, as evaluated on nanoscale features. The patterns also highlight the need for a balance between recrystallization and grain growth to impart optimized material properties, enabling the development of high-performance components for lightweight automotive structures and aerospace applications.\u003c/p\u003e\u003cp\u003e\u003c/p\u003e\u003c/div\u003e\u003cdiv id=\"Sec12\" class=\"Section2\"\u003e\u003ch2\u003e3.9. X-ray diffraction (XRD) result of modified AZ61 alloy under cast and rolled condition\u003c/h2\u003e\u003cp\u003eA detailed structural analysis is conducted using the X- ray diffraction test to provide clear insights into the phases developing in the stir cast alloys under different conditions (Fig.\u0026nbsp;\u003cspan refid=\"Fig9\" class=\"InternalRef\"\u003e9\u003c/span\u003e). The XRD results indicate the following: the primary phase is α- Mg matrix (Mg- Al solid solution), β-Mg\u003csub\u003e17\u003c/sub\u003eAl\u003csub\u003e12\u003c/sub\u003e, Mg\u003csub\u003e2\u003c/sub\u003eCa. The XRD analysis suggests that a small amount of the element Ca may dissolve in the Mg matrix, and any excess Ca would precipitate from the Mg\u003csub\u003e2\u003c/sub\u003eCa phases. It was rarely found in AZ 61, containing 0.2% Sc, 0.5% Ca, and 0.5% Mn, which is higher than 1% Mn due to the scarcity of the Ca element. A phase of Mn was not observed, likely because the amount of the Mn phase was small and did not reach the detection limit of the diffractometer. Scandium amounts to 0.2% by weight in this aluminum alloy. This predicts the precipitation of Al\u003csub\u003e3\u003c/sub\u003eSc upon thermal exposure. It is worth mentioning that the possible Al\u003csub\u003e3\u003c/sub\u003eSc phase did not exist in the stir- cast alloy, as shown by the XRD analysis. There could be two reasons for this. Initially, the Al\u003csub\u003e3\u003c/sub\u003eSc concentration could have been so minor that the peak could not be distinguished due to background noise. The second reason may be that Al\u003csub\u003e3\u003c/sub\u003eSc is dissolved in Mg\u003csub\u003e2\u003c/sub\u003eCa because of the different crystal structures. However, the precipitation of the secondary β-Mg\u003csub\u003e17\u003c/sub\u003eAl\u003csub\u003e12\u003c/sub\u003e phase in its casting condition (as revealed in Fig.\u0026nbsp;\u003cspan refid=\"Fig9\" class=\"InternalRef\"\u003e9\u003c/span\u003eb) contributes to enhancing the mechanical strength of the alloy due to the higher concentration of completely dissolved Al in the magnesium matrix. The microstructure of the treated sample transforms through a rolling treatment, resulting in an increased hardness number. Figure\u0026nbsp;\u003cspan refid=\"Fig9\" class=\"InternalRef\"\u003e9\u003c/span\u003ea and \u003cspan refid=\"Fig9\" class=\"InternalRef\"\u003e9\u003c/span\u003eb demonstrate that two T6- treated samples presented the same phase constitution stage; in other words, the α- Mg and the intermetallic β-Mg\u003csub\u003e17\u003c/sub\u003eAl\u003csub\u003e12,\u003c/sub\u003e but the process of microstructure evolution in the two T6- treated samples was the same yet varied depending on the grain size. A dendritic structure, resulting from the solidification of molten metal, developed with a slow cooling rate, and α- Mg and β-Mg\u003csub\u003e17\u003c/sub\u003eAl\u003csub\u003e12\u003c/sub\u003e were present in the as- cast sample.\u003c/p\u003e\u003cp\u003e\u003c/p\u003e\u003c/div\u003e\u003cdiv id=\"Sec13\" class=\"Section2\"\u003e\u003ch2\u003e3.10. Differential scanning calorimetric study (DSC) of cast condition AZ 61 alloy\u003c/h2\u003e\u003cp\u003eA precipitation kinetics assessment, indicated by the forming peak in (Fig.\u0026nbsp;\u003cspan refid=\"Fig10\" class=\"InternalRef\"\u003e10\u003c/span\u003ea), was conducted to further understand the aging response of the AZ61 alloy through a DSC study. Fewer than the exothermic peak at 83.5\u0026deg;C, there are smaller peaks at various temperatures. From the XRD pattern of the experimental alloy, it was observed that small peaks can be recognized at approximately 125\u0026deg;C and 175\u0026deg;C, and the exothermic peaks observed in the DSC heating cycle suggest that new phases were generated.\u003c/p\u003e\u003cp\u003e\u003c/p\u003e\u003cp\u003eThe activation energy for the larger peak appearing at 83.5\u0026deg;C is calculated using the Nagasaki-Maesono relationship [\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e], which is derived from the Arrhenius equation \u0026#119897;\u0026#119899; [∆\u0026#119862;\u0026#119901;(\u0026#119882;\u0026minus;\u0026#119908;)]\u0026thinsp;=\u0026thinsp;ln \u0026#119860;\u0026minus;\u0026#119864;/\u0026#119877;\u0026#119879;. This corresponds to ln, where Δ Cp is heat capacity, W is the area under the peak, \u0026lsquo;w\u0026rsquo; is the area of the shaded portion in (Fig.\u0026nbsp;\u003cspan refid=\"Fig10\" class=\"InternalRef\"\u003e10\u003c/span\u003eb), E represents activation energy, and R stands for the universal gas constant. In (Fig.\u0026nbsp;\u003cspan refid=\"Fig10\" class=\"InternalRef\"\u003e10\u003c/span\u003ec), the calculated activation energy is approximately 154.48 KJ/mol. The diffusion of aluminum at the grain boundaries in magnesium resulted in an activation energy of 144.5 KJ/mol [\u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e]. Based on the DSC results, it is concluded that the diffusion of aluminum in magnesium limits precipitation during aging, and Mg\u003csub\u003e17\u003c/sub\u003eAl\u003csub\u003e12\u003c/sub\u003e precipitates form at 83.9\u0026deg;C with the highest transformation rate.\u003c/p\u003e\u003c/div\u003e"},{"header":"4. Conclusion","content":"\u003cp\u003eIn this study, the microstructure of the modified AZ61 alloy is optimized by examining the β-Mg\u003csub\u003e17\u003c/sub\u003eAl\u003csub\u003e12\u003c/sub\u003e phase using advanced image processing techniques. High-resolution imaging and automated image analysis enable precise quantitative characterization of the β-Mg\u003csub\u003e17\u003c/sub\u003eAl\u003csub\u003e12\u003c/sub\u003e morphology, size, and spatial distribution. Consequently, the modification process enhances the phase itself, refining it; therefore, the dispersion becomes more homogeneous and the average particle size smaller. Furthermore, quantitative analysis of the interactions among these phases clarifies their role in the alloy's performance and introduces a novel approach to microstructural analysis utilizing an image processing-assisted method. This approach deepens the understanding of microstructure-property relations and allows for the design of tailored magnesium alloys to meet specific engineering demands. Based on a multi-scale approach that combines advanced metallographic and thermal measurements, insights into the β-Mg\u003csub\u003e17\u003c/sub\u003eAl\u003csub\u003e12\u003c/sub\u003e phase evolution and its structure-property synergy are revealed for the modified AZ61 magnesium alloy. The as-cast microstructure exhibits a thermal gradient of 550\u0026deg;C to 100\u0026deg;C due to a high central SANS intensity, coarse dendrites, and strong segregation of β-Mg\u003csub\u003e17\u003c/sub\u003eAl\u003csub\u003e12\u003c/sub\u003e at grain boundaries. These features lead to localized stress concentrations and reduce uniformity.\u003c/p\u003e\u003cp\u003eWhen the composite was rolled at 100\u0026deg;C, the β-Mg\u003csub\u003e17\u003c/sub\u003eAl\u003csub\u003e12\u003c/sub\u003e partially fragmented and the grains were moderately refined, giving more uniform phase distribution, which is evidenced by lower SANS intensity and initial textural alignment. 200\u0026deg;C Dynamic recrystallization led to equiaxed grains and decreased secondary arm spacing, promoting greater isotropy and phase connectivity. This state naturally increased ductility and reduced intergranular corrosion threats. The fine-grained microstructure and the uniform SANS scattering in the 300\u0026deg;C rolled material should also bring potential enhancements in the thermal stability and reduction of anisotropy. 400\u0026deg;C, the fully recrystallized and grain expanded structure resulted, which was also very homogeneous and suitable for ductility and corrosion resistance at the expense of tensile strength. The role of the β-Mg\u003csub\u003e17\u003c/sub\u003eAl\u003csub\u003e12\u003c/sub\u003e phase evolution and grain refinement are highlighted as the key factors in the alloy properties tailoring. This study outlines a framework that this work relies upon the incorporation of image processing for the optimized microstructural design, providing the groundwork for future studies aimed at producing lightweight alloys applicable for automotive and aerospace engineering industries.\u003c/p\u003e"},{"header":"Declarations","content":"\u003cp\u003e\u003ch2\u003eDeclaration of Competing Interest\u003c/h2\u003e\u003cp\u003eThe authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.\u003c/p\u003e\u003c/p\u003e\u003ch2\u003eFunding\u003c/h2\u003e\u003cp\u003eThis research did not receive any funding.\u003c/p\u003e\u003ch2\u003eAuthor Contribution\u003c/h2\u003e\u003cp\u003eConceptualization: Amit Tiwari, Aman SharmaMethodology: Amit Tiwari, Sasmita NayakFormal Analysis and Investigation: Amit Tiwari, Ginika MahajanResources and Materials: Aman Sharma, Ginika MahajanData Curation and Image Processing: Sasmita Nayak, Amit TiwariWriting \u0026ndash; Original Draft Preparation: Amit TiwariWriting \u0026ndash; Review \u0026amp; Editing: Aman Sharma, Sasmita NayakVisualization (Figures, Graphs, and Image Analysis): Sasmita NayakSupervision and Project Administration: Aman Sharma\u003c/p\u003e\u003ch2\u003eAcknowledgement\u003c/h2\u003e\u003cp\u003eThe authors wish to acknowledge the support received from the Suresh Gyan Vihar University while conducting the research.\u003c/p\u003e\u003ch2\u003eData Availability\u003c/h2\u003e\u003cp\u003eThe data that support the findings of this study are available from the corresponding author, upon reasonable request.\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\u003cli\u003e\u003cspan\u003eArora, G. S., Saxena, K. K., Mohammed, K. A., Prakash, C., \u0026amp; Dixit, S. (2022). Manufacturing Techniques for Mg-Based Metal Matrix Composite with Different Reinforcements. \u003cem\u003eCrystals\u003c/em\u003e, \u003cem\u003e12\u003c/em\u003e(7), 945. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.3390/cryst12070945\u003c/span\u003e\u003cspan address=\"10.3390/cryst12070945\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eBaek, S., Kim, J., Min, D., \u0026amp; Park, S. S. (2023). Remarkably slow corrosion rate of high-purity Mg microalloyed with 0.05wt% Sc. \u003cem\u003eJournal of Magnesium and Alloys\u003c/em\u003e, \u003cem\u003e11\u003c/em\u003e(3), 991\u0026ndash;997. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1016/j.jma.2022.08.003\u003c/span\u003e\u003cspan address=\"10.1016/j.jma.2022.08.003\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eBanerjee, M. K., Tiwari, A., \u0026amp; Kumar, N. (2023). Ageing characteristics of stir cast AZ 61 alloy with minor additions. \u003cem\u003eRecent Patents on Engineering\u003c/em\u003e, \u003cem\u003e18\u003c/em\u003e. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.2174/1872212118666230609122741\u003c/span\u003e\u003cspan address=\"10.2174/1872212118666230609122741\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eBian, M., Sasaki, T., Suh, B., Nakata, T., Kamado, S., \u0026amp; Hono, K. (2017). A heat-treatable Mg\u0026ndash;Al\u0026ndash;Ca\u0026ndash;Mn\u0026ndash;Zn sheet alloy with good room temperature formability. \u003cem\u003eScripta Materialia\u003c/em\u003e, \u003cem\u003e138\u003c/em\u003e, 151\u0026ndash;155. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1016/j.scriptamat.2017.05.034\u003c/span\u003e\u003cspan address=\"10.1016/j.scriptamat.2017.05.034\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eChang, W., Shen, Y., Su, Y., Zhao, L., Zhang, Y., Chen, X., Sun, M., Dai, J., \u0026amp; Zhai, Q. (2019). Grain refinement of AZ91 magnesium alloy induced by AL-V-B Master alloy. \u003cem\u003eMetals\u003c/em\u003e, \u003cem\u003e9\u003c/em\u003e(12), 1333. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.3390/met9121333\u003c/span\u003e\u003cspan address=\"10.3390/met9121333\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eChaudry, U. M., Hamad, K., \u0026amp; Jun, T. (2022). Investigating the microstructure, crystallographic texture and mechanical behavior of Hot-Rolled pure MG and MG-2AL-1ZN-1CA alloy. \u003cem\u003eCrystals\u003c/em\u003e, \u003cem\u003e12\u003c/em\u003e(10), 1330. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.3390/cryst12101330\u003c/span\u003e\u003cspan address=\"10.3390/cryst12101330\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eSoni, P. K., Tiwari, A., Nayak, S., Vasnani, H., \u0026amp; Jha, S. K. (2024b). Ultrafine grain refinement and improved mechanical strength of compositionally modified AZ 61 alloy composite. In \u003cem\u003eAdvances in chemical and materials engineering book series\u003c/em\u003e (pp. 327\u0026ndash;362). \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.4018/979-8-3373-0669-8.ch009\u003c/span\u003e\u003cspan address=\"10.4018/979-8-3373-0669-8.ch009\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eChen, X., Zhang, D., Zhao, Y., Feng, J., Jiang, B., \u0026amp; Pan, F. (2020). Microstructure modification and precipitation strengthening for Mg\u0026ndash;6Zn\u0026ndash;1Mn\u0026ndash;4Sn\u0026ndash;0.5Ca through extrusion and aging treatment. \u003cem\u003eTransactions of Nonferrous Metals Society of China\u003c/em\u003e, \u003cem\u003e30\u003c/em\u003e(10), 2650\u0026ndash;2657. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1016/s1003-6326(20)65409-7\u003c/span\u003e\u003cspan address=\"10.1016/s1003-6326(20)65409-7\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eCheng, K., Zheng, Y., Sun, J., Zhao, Y., Wang, J., Yu, H., Zhao, D., Li, H., Zhou, J., Ma, Z., Wang, J., Guo, C., Wang, X., Zhang, L., \u0026amp; Du, Y. (2023). Investigation on the temperature-dependent diffusion growth of intermetallic compounds in the Mg-Al-Zn system: Experiment and modeling. \u003cem\u003eJournal of Magnesium and Alloys\u003c/em\u003e. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1016/j.jma.2023.02.009\u003c/span\u003e\u003cspan address=\"10.1016/j.jma.2023.02.009\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eTiwari, A., Kumar, N., \u0026amp; Banerjee, M. K. (2023). Effect of Hot Rolling on Microstructure and Mechanical Properties of Stir Cast AZ 61 Alloy with Minor Additions. \u003cem\u003eIndian Journal of Science and Technology\u003c/em\u003e, \u003cem\u003e16\u003c/em\u003e(24), 1810\u0026ndash;1822. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.17485/ijst/v16i24.302\u003c/span\u003e\u003cspan address=\"10.17485/ijst/v16i24.302\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eCho, D. H., Avey, T., Nam, K. H., Dean, D., \u0026amp; Luo, A. A. (2022). In vitro and in vivo assessment of squeeze-cast Mg-Zn-Ca-Mn alloys for biomedical applications. \u003cem\u003eActa Biomaterialia\u003c/em\u003e, \u003cem\u003e150\u003c/em\u003e, 442\u0026ndash;455. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1016/j.actbio.2022.07.040\u003c/span\u003e\u003cspan address=\"10.1016/j.actbio.2022.07.040\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eDing, Y., Shi, Z., Li, Z., Jiao, S., Hu, J., Wang, X., Zhang, Y., Wang, H., \u0026amp; Guo, X. (2022). Effect of CNT content on microstructure and properties of CNTs/Refined-AZ61 Magnesium matrix composites. \u003cem\u003eNanomaterials\u003c/em\u003e, \u003cem\u003e12\u003c/em\u003e(14), 2432. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.3390/nano12142432\u003c/span\u003e\u003cspan address=\"10.3390/nano12142432\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eDong, X., Feng, L., Wang, S., Nyberg, E. A., \u0026amp; Ji, S. (2021). A new die-cast magnesium alloy for applications at higher elevated temperatures of 200\u0026ndash;300\u0026deg;C. \u003cem\u003eJournal of Magnesium and Alloys\u003c/em\u003e, \u003cem\u003e9\u003c/em\u003e(1), 90\u0026ndash;101. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1016/j.jma.2020.09.012\u003c/span\u003e\u003cspan address=\"10.1016/j.jma.2020.09.012\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eTiwari, N. A. (2024). Prediction model for hardness and tensile strength of graphene reinforced AZ 61 alloy based composite using Metaheuristic Algorithm. \u003cem\u003eGlobal Journal of Engineering and Technology Advances\u003c/em\u003e, \u003cem\u003e20\u003c/em\u003e(3), 042\u0026ndash;052. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.30574/gjeta.2024.20.3.0167\u003c/span\u003e\u003cspan address=\"10.30574/gjeta.2024.20.3.0167\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eR. Venkatesh, C. Ramesh Kannan, S. Manivannan, M. Vivekanandan, J. Phani Krishna, Amine Mezni, Saiful Islam, S. Rajkumar, \u0026ldquo;Synthesis and Experimental Investigations of Tribological and Corrosion Performance of AZ61 Magnesium Alloy Hybrid Composites\u0026rdquo;, Journal of Nanomaterials, vol. 2022, Article ID 6012518, 12 pages, 2022. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1155/2022/6012518 n.d\u003c/span\u003e\u003cspan address=\"10.1155/2022/6012518 n.d\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eHuang, SJ., Subramani, M., Ali, A.N. et al. The Effect of Micro-SiCp Content on the Tensile and Fatigue Behavior of AZ61 Magnesium Alloy Matrix Composites. Inter Metalcast 15, 780\u0026ndash;793 (2021). \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1007/s40962-020-00508-0 n.d\u003c/span\u003e\u003cspan address=\"10.1007/s40962-020-00508-0 n.d\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eSong-Jeng Huang, Murugan Subramani, Chao-Ching Chiang, Effect of hybrid reinforcement on microstructure and mechanical properties of AZ61 magnesium alloy processed by stir casting method, Composites Communications, Volume 25, 2021, 100772, ISSN 2452\u0026thinsp;\u0026ndash;\u0026thinsp;2139, \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1016/j.coco.2021.100772\u003c/span\u003e\u003cspan address=\"10.1016/j.coco.2021.100772\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e. n.d.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eLiu, W., Jiang, B., Luo, S. et al. Mechanical properties and failure behavior of AZ61 magnesium alloy at high temperatures. J Mater Sci 53, 8536\u0026ndash;8544 (2018). \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1007/s10853-018-2125-7 n.d\u003c/span\u003e\u003cspan address=\"10.1007/s10853-018-2125-7 n.d\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eZhaohui Shan, Yixia Zhang,, Bin Shan Wang, Qiang Zhang, Jianfeng Fan; Microstructural evolution and precipitate behavior of an AZ61 alloy plate processed with ECAP and electropulsing treatment, Journal of Materials Research and Technology, Volume 19, July\u0026ndash;August 2022, Pages 382\u0026ndash;390 n.d.\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eJiangfeng Song, Jia She, Daolun Chen, Fusheng Pan, Latest research advances on magnesium and magnesium alloys worldwide, Journal of Magnesium and Alloys, Volume 8, Issue 1, 2020, Pages 1\u0026ndash;41, ISSN 2213\u0026ndash;9567, \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1016/j.jma.2020.02.003\u003c/span\u003e\u003cspan address=\"10.1016/j.jma.2020.02.003\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e.\u003c/span\u003e\u003c/li\u003e\u003c/ol\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"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":"Small-Angle Neutron Scattering (SANs), Grain refinement, β-Mg17Al12 phase, Microstructure analysis, DSC analysis","lastPublishedDoi":"10.21203/rs.3.rs-7619268/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-7619268/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003eOptimizing the microstructure is one of the key processes to achieve the desired mechanical properties for magnesium alloys, such as the AZ61 alloy, which is extensively used in lightweight applications. This study further investigates advanced image processing of the β-Mg\u003csub\u003e17\u003c/sub\u003eAl\u003csub\u003e12\u003c/sub\u003e phase, a crucial intermetallic compound that determines strength and ductility. We developed a novel characterization approach that integrates high-resolution microscopy with automated image segmentation and quantitative analysis to enhance the characterization of the morphology, distribution, and volume fraction of the β-Mg\u003csub\u003e17\u003c/sub\u003eAl\u003csub\u003e12\u003c/sub\u003e phase. The AZ61 alloy underwent controlled thermo-mechanical processing to produce a modified form, resulting in the introduction of refined microstructural features. Furthermore, image analysis indicated significant microstructural evolution, including a homogeneous distribution and coarsening suppression of the β-Mg\u003csub\u003e17\u003c/sub\u003eAl\u003csub\u003e12\u003c/sub\u003e phase, based on process modification. The novelty of this study lies in our application of an image processing technique to the actual images of the sample's cross-sectional area, which allowed us to analyze the β-Mg\u003csub\u003e17\u003c/sub\u003eAl\u003csub\u003e12\u003c/sub\u003e phase effectively and understand how it contributes to optimizing the properties. It establishes a new baseline in accuracy and efficiency for mapping microstructural features that influence mechanical performance. DSC analysis was conducted to study the kinetics of phase transformation, employing advanced imaging techniques such as Small-Angle Neutron Scattering (SANs), solidification thermal mapping, and temperature distribution studies to analyze microstructural evolution.\u003c/p\u003e","manuscriptTitle":"Multi Scale Analysis of Modified AZ61 Alloy Evolution of β-Mg17Al12 Phase and Structure–Property Correlation","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2025-10-28 02:11:20","doi":"10.21203/rs.3.rs-7619268/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":"bca617ea-1a00-4bf9-a997-bf507792448f","owner":[],"postedDate":"October 28th, 2025","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"posted","subjectAreas":[],"tags":[],"updatedAt":"2025-12-01T00:53:22+00:00","versionOfRecord":[],"versionCreatedAt":"2025-10-28 02:11:20","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-7619268","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-7619268","identity":"rs-7619268","version":["v1"]},"buildId":"8U1c8b4HqxoKbykW_rLl7","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}