Toughness Of Alloy Research Articles

Machine learning-based forward and inverse designs for prediction and optimization of fracture toughness of aluminum alloy

Utilization of machine learning framework to design aluminum alloy with high fracture toughness is increasing. Nonetheless, before such model can be applied, the generalizability of the model becomes imperative thus it can give a better performance not only in the present, but also against the future data. In this work, shallow and deep machine learning techniques represented by support vector regression (SVR), k-nearest neighbors (KNN), extreme gradient boosting (XGBoost) and artificial neural network (ANN) was deployed to predict the fracture toughness of various aluminum alloys in the scheme of MLDS framework. Our study reveals that the highest prediction accuracy can be obtained for XGBoost technique with R2 score, RMSE, and MAPE values were found to be 90.6 %, 2.57, and 7.0 %, respectively with robust k-fold validation value of 90.1 ± 1.5. The superior performance of Xgboost due to its capability handling non-linear regression problems with a small amount of data.The forward properties to compositions (P2C) and reverse compositions to properties (C2P) models exhibited good accuracies in predicting the fracture toughness as illustrated by the error values lower than the machine learning design system (MLDS) error criteria of 5 %. The XGBoost model feasibility to predict fracture toughness for various aluminum alloys of Alcoa 7055-T7751, AA 7055-T7751, 2024-T852, 5083-O 8090-T8151 was demonstrated as well as used to search aluminum alloy compositions with high fracture toughness. The Pearson correlation coefficient (PCC) and feature Importance results were able to reveal the effects of the alloying elements to the fracture toughness of the alloy. These results reveal the potential application of our models as a pre-screening tool in selecting material for alloying compounds.

Effect of aging temperatures on the microstructure and mechanical properties of TC21 forgings with basket–weave microstructure

This study aims to explore the influence of various aging temperatures on the microstructure and mechanical properties of TC21 forgings. Basket-weave microstructures were prepared via quasi-β forging followed by annealed at 900 °C for 1.5 h and aged at 530 °C, 560 °C, and 590 °C for 4 h, and then their tensile performance, impact toughness, and fracture toughness were examined. Results indicate that higher aging temperatures not only facilitate the segregation of Al element, resulting in a reduction in the effective size (dαlaths, the width/length ratio) of primary α laths (αlaths) and their amount, but also promote phase transition, inducing an increase in the effective size (dαfine) of secondary fine α (αfine) lamellae. While both dαlaths−1/2 and dαfine−1/2 have a linear relationship with the strength, which was analyzed using the Hall–Petch relationship, the more pronounced interface strengthening effect and hindering crack propagation mainly results from the αlaths. Moreover, the plasticity declines significantly as the proportion of the αlaths phases decreases. Thus, for strength and plasticity, the αlaths are a much more important factor than the αfine lamellae. However, although the synergistic deformation and fracture of both the αlaths and αfine phases can consume a larger impact initiation energy, the enhancement of the impact energy of the alloy is primarily related to a high precipitation amount of the αfine lamellae. Furthermore, the decrease in dαlaths promotes the misorientation and accumulation of dislocations between αlaths interfaces, hindering the enhancement of KIC (fracture toughness) by forming transgranular fractures. Conversely, the increase in KIC attributed to the energy consumed in the plastic deformation region at the crack tip, due to the αfine lamellae compensates for the energy, resulting in a reduction in the crack propagation path. Therefore, the αfine lamellae may play a more crucial role in increasing the toughness of alloys, in particular the impact toughness of the TC21 alloy.

Study on the Aging Precipitation Behavior and Kinetics of Al-10.0Zn-3.0Mg-2.8Cu Alloy by Pre-Deformation Treatment.

In this paper, the effect of thermomechanical treatment process on the hardening behavior, grain microstructure, precipitated phase, and tensile mechanical properties of the new high-strength and high-ductility Al-10.0Zn-3.0Mg-2.8Cu alloy was studied, and the optimal thermomechanical treatment process was established. The strengthening and toughening mechanisms were revealed, which provided technical and theoretical guidance for the engineering application of this kind of high strength-ductility aluminum alloy. Al-10.0Zn-3.0Mg-2.8Cu alloy cylindrical parts with external longitudinal reinforcement were prepared by a composite extrusion deformation process (reciprocal upsetting + counter-extrusion) with a true strain up to 2.56, and the organizational evolution of the alloys during the extrusion deformation process and the influence of pre-stretching treatments on the subsequent aging precipitation behaviors and mechanical properties were investigated. The results show that firstly, the large plastic deformation promotes the fragmentation of coarse insoluble phases and the occurrence of dynamic recrystallization, which results in the elongation of the grains along the extrusion direction, and the volume fraction of recrystallization reaches 42.4%. Secondly, the kinetic study showed that the decrease in the activation energy of precipitation increased the nucleation sites, which further promoted the diffuse distribution of the second phase in the alloy and a higher number of nucleation sites, while limiting the coarsening of the precipitated phase. When the amount of pre-deformation was increased from 0% to 2%, the size of the matrix precipitated phase decreased from 5.11 μm to 4.1 μm, and when the amount of pre-deformation was increased from 2% to 7%, the coarsening of the matrix precipitated phase took place, and the size of the phase increased from 4.1 μm to 7.24 μm. The finalized heat treatment process for the deformation of the aluminum alloy tailframe was as follows: solution (475 °C/3 h) + 2% pre-stretching + aging (120 °C/24 h), at which the comprehensive performance of the alloy was optimized, with a tensile strength of 634.2 MPa, a yield strength of 571.0 MPa, and an elongation of 15.2%. The alloy was strengthened by both precipitation strengthening and dislocation strengthening. After 2% pre-stretching, the fracture surface starts to be dominated by dense tough nest structure, and most of them are small tough nests, and small and dense tough nests are the main reason for the increase in alloy toughness after 2% pre-stretching deformation.

Anomalous increase of fracture toughness of TiAl-based alloys at high temperature

The anomalous increase of mechanical property of TiAl-based alloys at high temperature caters to the property requirements as the high-temperature structural materials, which is thus important and worth studying. However, people currently are not clear whether the fracture toughness of TiAl-based alloys has an anomalous increase at high temperature, and if so, how much it increases, and why it increases. In order to answer these questions, the forged Ti-44Al-8Nb model alloy with fine and uniform microstructure was used. The fracture toughness of the alloy at different temperatures was tested. The results indicated that the alloy did show an anomalous increase of fracture toughness at 700 °C–800 °C. The main crack deflected a large angle at 700 °C, and terminated at the upper part at 750 °C and 800 °C. The fracture morphology was fine, and the cleavage plane became smaller and less at high temperature. These characteristics corresponded to the anomalous increase of fracture toughness at high temperature. Through reverse thinking, we found that the high dislocation density was the root causing the anomalous increase of fracture toughness at high temperature. The forging-induced texture, such as B2 〈100〉//RD and γ-TiAl 〈011]//RD could also promote the dislocations slip on the main slip surfaces during the high temperature fracture toughness test, contributing to the final high dislocation density. The critical crack size at 700 °C–800 °C was about 4 times that of room temperature, corresponding to the higher fracture toughness of the alloy at high temperature.

Effects of TaB2 addition on microstructure and mechanical properties of Nb[sbnd]Si based alloys

The effects of TaB2 addition on the Nb-16Si-22Ti-3Al alloy were investigated in this study. The results showed that the Nb-16Si-22Ti-3Al alloy consisted of the Nbss phase, α-Nb5Si3 phase, Nb3Si phase, and Tiss phase. With the addition of TaB2 increased from 0 to 0.25 at. %, the Nb3Si disappeared and the eutectic transformation reaction occurred (Nb3Si → Nbss + α-Nb5Si3), which made the volume fraction of the Nbss phase increased from 38.6% to 50.3%. With the TaB2 addition further increasing to 2.0 at. %, the α-Nb5Si3 became the primary phase, and the microstructure transformed from the Nbss + α-Nb5Si3 eutectic structure to the primary α-Nb5Si3 and (Nbss + γ-Nb5Si3) hypereutectic structure. The alloy with 0.25 at. % TaB2 addition had the highest fracture toughness of 10.2 MPa•m1/2 due to the refinement of microstructure and the increment of ductile Nbss. The maximum compressive strength of TaB2 added alloy at room temperature reached 2587.25 MPa in 2.0TaB2 specimen, owing to the solid solution strengthening of Ta and B, and the increment of the silicides content. Additionally, by comparing the fracture toughness of alloys with TaB2 addition obtained by three-point bending (SENBs) and indentation methods, respectively, the feasibility of estimating the fracture toughness of NbSi based alloys by the indentation method is demonstrated with an error of below 20%, which provided a basis for subsequent rapid performance characterization.

Effects of multi-scale precipitated phases on the toughness of FeCrAl alloy investigated by varying cooling mode and RE doping

In order to clarify the factors affecting the toughness of FeCrAl alloy, a systematic investigation on the correlation between microstructure and mechanical properties of hot-rolled 0Cr21Al6 sheet was performed through regulating cooling rate and rare earth (RE) element added in the alloy. It is worked out that a slower cooling rate results in the increase of brittleness for the alloy mainly due to nanoscale α' precipitates, while RE element promotes recrystallization and hinders the precipitation of sub-micron (Ti,Nb)P, which is beneficial to improving the toughness of alloy. These findings offer a valuable technical guidance for enhancing the toughness of FeCrAl alloy.

Study of low-temperature impact deformation behavior of Ti–6Al–4V alloy

The impact behavior of the Ti–6Al–4V alloy has been investigated at varying temperatures (298 K, 223 K, 77 K) in this study. The results reveal a decrease in toughness with reduced temperature, with notable changes in energy distribution between crack initiation and propagation. The {101¯2}α twins formed in the studied sample under impact loading at 298 K and 223 K, and were absent at 77 K. The formation and propagation of twins contribute to the higher toughness of the 298 K and 223 K samples. These findings would provide valuable guidance to optimize the Ti–6Al–4V alloy toughness in low-temperature environments.

Effect of Temperature and Ageing on Fracture Toughness of Alloy 617M

In recent years, Advanced Ultra Super Critical (AUSC) plants have used Ni-Cr-Co-Mo based alloy 617M for high-temperature components like steam piping and rotors, where material resistance against fracture after prolonged exposure in a hostile environment is a matter of concern to the designers. To this end, fracture toughness characterization of the material in as-received and aged conditions using an elastic-plastic fracture mechanics (J-R curves) approach can provide a significant input towards the component integrity assessments at service conditions. In this study, J-R curves of the alloy 617M have been determined for the as-received and differently aged (up to 20000 h at 710 °C) conditions using compact tension (CT) specimens following ASTM E 1820-13. Repeated tests have been carried out at temperatures 27 °C, 650 °C, 710 °C and 750 °C. The fracture toughness (JIC) thus determined, has shown a declining trend with test temperatures. This attributes to the ease of the crack initiation process owing to the γ′ induced matrix hardening and subsequent ageing-inducing precipitations of M23C6 carbides at the grain boundaries.

Degradation and anisotropy characteristics of fracture toughness in Ni-based superalloys after phase coarsening

The effect of phase coarsening on the crack propagation characteristics and the corresponding fracture toughness in Ni-based superalloys is investigated by integrating with the finite element method simulations and related mechanism analysis, and the relationship between the macroscopic mechanical properties of alloys and the evolution in their microstructures are discussed in detail. Related analysis shows that the fracture toughness of alloys degraded considerably with phase coarsening. Moreover, the fracture toughness also demonstrates an anisotropic characteristic. Specifically, when the volume fraction of precipitate is low or the degree of phase coarsening is relatively low, the fracture toughness of alloys increases first and then decreases gradually along with increasing the loading angle, showing an inverted "V" shape. In comparison, in the case of a higher volume fraction of precipitate or higher degree of phase coarsening, the fracture toughness displays an opposite variation trend, and reaches the minimum value at the loading direction of 45°. The corresponding variation characteristics of fracture toughness are correlated with the evolutions of precipitate shape, size, and distribution within the alloys. The change in the microstructure or that in the loading direction affects remarkably the initiation and growth of micro-voids within the alloys, and it further affects the crack propagation characteristics, resulting in the degradation and anisotropy characteristics of macroscopic fracture toughness in the alloys. Related work is of great significance for the structure design of Ni-based superalloys components, the mechanical property evaluation and the life prediction during their service process.

Two-Body and Three-Body Abrasive Wear Behaviors of Fe-2wt%B Alloy Modified With Various K2SO4 Additions

Fe-B alloy is a candidate for a low-cost wear-resistant material but shows very low fracture toughness. To improve the toughness of Fe-B alloys, for this study we attempted to break the continuous network of eutectic Fe2B via K2SO4 addition and heat treatment, so that the Fe2B particles transform to be more spherical. The microstructure, mechanical properties, and two-body and three-body abrasive wear behaviors of the alloys modified with various K2SO4 additions were systemically investigated. The results show that the heat-treated alloys mainly consist of martensite and M2B (M = Cr, Mn, Fe, etc.). With the addition of K2SO4, a new phase α-MnS forms in the alloy, and the circularity value of M2B increases from 0.13 to 0.44. The impact toughness of alloy increases from 6.09 J/cm2 to 14.72 J/cm2 with an increment of 142%, although the Rockwell hardness does not show obvious change. Meanwhile, the two-body wear weight loss of alloys exhibits a “decrease and then increase” trend with increasing K2SO4 addition, while the three-body wear weight loss decreases first and then remains unchanged. The different wear behaviors were investigated and discussed.

Precipitation behavior of γ′ precipitates in 21Cr-32Fe-41Ni heat-resistant alloy at different aging temperatures

The precipitation behavior of γ′ precipitates and mechanical properties of 21Cr-32Fe-41Ni alloy at different aging temperatures were investigated by scanning electron microscopy, transmission electron microscopy, chemical phase analysis, mechanical property tests. The results showed that the precipitates in 21Cr-32Fe-41Ni alloy included γ′ precipitates, MC phases, σ phases after aging heat treatment. There were two precipitation modes of γ′ precipitates: intragranular dispersed precipitation and grain boundary discontinuous precipitation. The number and size of intragranular γ′ precipitates increased with the increase in aging temperature. During the coarsening process, the γ′ precipitates were kept spherical. When the aging temperature was above 740 ℃, the discontinuous precipitation reaction occurred under the combined effect of grain boundary migration and solute diffusion-controlled equilibrium phase growth. According to SEM images, there were four different kinds of morphologies of discontinuous precipitated cellular γ′ at the grain boundaries. They were lamellae precipitates, short rod precipitates, granular precipitates and bidirectional parallel precipitates. When the aging temperature was between 650 ℃ and 740 ℃, the strength of the alloy increased rapidly due to the precipitation of a large number of intragranular spherical γ′, and the precipitation of grain boundary cellular γ′ was one of the main reasons for the toughness of alloy decreased rapidly above 740 ℃.

Effect of Aging on Impact Toughness and Fracture Behavior of Three Wrought Aluminum Alloys

Herein, the effect of the aging state on the impact toughness of three typical wrought Al alloys (7075, 2024, and 6A01) is investigated. At room temperature, the fracture mode of the three aluminum alloys at different aging states is a ductile transgranular fracture. At low temperatures, high‐strength aluminum alloys exhibit a mixture fracture of transgranular and intergranular, while medium‐strength aluminum alloys are still dominated by transgranular fractures. The effect of the aging state on the impact toughness of aluminum alloys was analyzed based on the deformation mechanism and morphology near grain boundaries. The underaged state with planar slip dislocations exhibits good plasticity and work‐hardening ability, which reduces the strain localization caused by dislocation plugging and thus improves the impact toughness of the alloy. Furthermore, the fine grain boundary precipitates and the narrow precipitation‐free zone of the underaged increase the uniform deformation capacity near the grain boundaries and inhibit the initiation and propagation of cracks. Compared with high‐strength aluminum alloys, medium‐strength aluminum alloys exhibit higher impact toughness due to the formation of a larger plastic zone and shear lip area during impact.

Study on the Subcritical Quenching Process of High-Chromium Cast Iron Prepared by Squeeze Casting

In this study, the heat treatment process of a high-chromium cast iron (HCCI) alloy prepared via 128 MPa squeeze casting at different subcritical quenching temperatures was investigated. The results showed that subcritical heat treatment can change the martensite content, the carbide type and size of the squeeze casting HCCI microstructure. Furthermore, it was revealed that the subcritical quenching heat treatment can improve the hardness of the liquid-forged HCCIs. When the quenching temperature increased from 500 °C to 530 °C, the hardness of the alloy increased significantly, reaching a maximum value of 57 HRC. Thereafter, if the temperature continued to rise to 630 °C, the hardness decreased rapidly. For impact toughness, when the quenching temperature was 500 °C, the toughness of alloy increased by 0.9 J/cm2 than that of the no heat treatment group. If the quenching temperature continued to increase, the toughness was reduced. Taking hardness and toughness into account, the microstructure evolution diagram of the optimal process-500 °C subcritical quenching process was established, various characterisation techniques were used to gain insights into the optimal heat treatment process. Compared with high temperature heat treatment, subcritical heat treatment can improve the performance of the HCCI alloy and reduce costs.

Process parameters and TiAlN coating impact on microwire-EDM of Ti6Al4V using PVD technique in biomedical application

The growing demand for products made of cutting-edge materials with increased attributes motivates material scientists to investigate prospective variants of such materials. Among the various categories of life-saving advanced materials are biomaterials, although shaping most of them according to the needs encounter manufacturing constraints due to their specific mechanical properties. For example, the extremely tough alloy Ti6Al4V, is renowned for its outstanding mechanical compatibility with the human body. Nonconventional means of machining have gained popularity keeping focus on the challenging machining circumstances that are well-known for their very precision and machining accuracy, no matter what type, shape, or hardness is being machined. Electrical discharge machining (EDM), for example, is the most prevalent efficient means of material removal, along with wire EDM (WEDM), [Formula: see text]-WEDM, and so on. Excess material should be removed for more particular applications of complex and baroque shapes, with a high degree of smoothing and finish, is one of the most advantageous characteristics of wedding metal dielectric material ([Formula: see text]-WEDM). In this study, we examined the effect of variable pulse-on (Ton), pulse (Toff), time (to), flushing pressure (FP), wire feed rate (WFR), wire tension (WT), voltage (SV), and peak current (PC) on [Formula: see text]-WEDM’s reliability of the machined section (SR) using physical vapor deposition (PVD) technique to deposit aluminium nitride (TiAlN) coating on the surface of the metal. The results demonstrate a substantial reduction in roughness in the mechanically produced surfaces, further demonstrating, and confirming the biocompatibility of metals dielectric materials ([Formula: see text]-WEDM) with tissues within the human body.

Effect of annealing temperature on as-cast Ti6Al4V–5Cu alloy microstructure, tensile properties, and fracture toughness

The effects of annealing temperature on the microstructure, tensile properties, hardness, and fracture toughness of an as-cast Ti6Al4V-5Cu alloy with a lamellar microstructure were investigated. Following annealing treatment in the range of 740-940 ℃ , the phase thicknesses in the alloy are changed. The α lamellar thickness was found in a range of 1.28-7 µm and β-phase thickness in a range of 0.35-2.3 µm. For higher ductility and good fracture toughness, higher annealing temperatures were desirable. The α- lamellar thickness was an important microstructural feature influencing the fracture toughness. Lowering the thickening of α platelet/ lamellar structure could enhance the fracture toughness of the as-cast Ti6Al4V-5Cu alloy. At various annealing temperatures, the Ti6Al4V-5Cu alloy exhibited varying degrees of deformation resistance. The elongation percentage of the alloy increased with annealing temperature. The effect of the change in annealing temperature on the hardness (HV) of the alloy exhibited a zig-zag profile. The hardness of the alloy was not related to the phase thickness. The crack path tortuosity and nature of plastic deformation, particularly on the α/β interface structure, were also important influencing factors in fracture toughness. Good plasticity and a regularly tortuous crack propagation path were both favorable for the fracture toughness of the alloy.

Effect of three-dimensional deformation at different temperatures on microstructure, strength, fracture toughness and corrosion resistance of 7A85 aluminum alloy

In this study, 7A85 aluminum alloy was subjected to 20% three-dimensional (3D) deformation at different temperatures (−196, 25, 250, and 480 °C), followed by solid solution, water quenching, 3% cold deformation, and retrogression and re-aging (RRA) treatment. The microstructural evolution and 3D mechanical properties, fracture toughness, electrical conductivity, and corrosion resistance of the alloy under different deformation processes were analyzed for comparison. The results indicated that conducting the 3D deformation process prior to solution treatment significantly improved the strength and fracture toughness of the alloy as compared to the undeformed (UD) specimen, and maintained its good corrosion resistance under the RRA treatment. In addition, with the decrease of the deformation temperature, the greater flow stress strongly sheared and crushed the coarse second-phase particles into fine particles, thus facilitating their full dissolution in the aluminum matrix during subsequent solution treatment and increasing the driving force for aging precipitation. Furthermore, more dislocations were introduced at low-temperature deformation, thus providing more nucleation sites for static recrystallization during solution treatment and refining grains. Ultimately, the densest precipitates and the finest equiaxed grains with the narrowest grain boundary precipitate-free zones (PFZs) were acquired for the cryogenic deformation (CD) sample, resulting in the highest ultimate tensile strength (UTS), elongation (EL) with the least anisotropy, and fracture toughness of the CD specimen. The optimal comprehensive performance was obtained for the CD specimen with the average 3D UTS, average 3D yield strength (YS), average 3D EL, and fracture toughness of 545 MPa, 476 MPa, 16%, and 42.49 MPa·m1/2, respectively, which were respectively 2.3%, 0.2%, 18.5%, and 21.4% higher than those of the UD specimen.

Влияние поперечно-винтовой прокатки с контролируемой закалкой на механические свойства и ударную вязкость титанового сплава

The paper studies the evolution of the structure, phase composition, and impact toughness of the Ti-6Al-3Mo titanium alloy after two types of processing, one of them is included heating and hot helical rolling with quenching in water (mode I). The additional air quenching is used between the rolling and quenching processes in mode II. This approach with combining two cooling stages (in air and in water) of the alloy makes possible to control the recrystallization time and form a gradient structure over the cross-section of the bar stock. The processing of titanium alloy according to mode I lead to decrease of impact strength. The addition of air-cooling stage (in mode II) leads to insignificant decrease hardness and increase toughness of alloy. The treatment by mode I and II of the titanium alloy lead to formation of the structure which contain large grains of the primary α-phase in thin-plate structure of the secondary α-phase in the β-phase. It is shown that the obtained structure states of alloy affect to crack propagation under impact loading and changing the amount of energy which spent to the complete destruction of the samples.

Influence of B contents on the microstructure, fracture toughness and oxidation resistance of Mo-Si-B alloys

The Mo-10Si-(0, 5, 10, 15)B (at.%) alloys located in Moss (Mo solid solution) +Mo3Si +T2 (Mo5SiB2) region were prepared by arc melting. The effect of B content on the microstructure, microhardness, fracture toughness and oxidation resistance of the alloys was studied. In the Mo-10Si alloy, there are primary Moss and peritectic Mo3Si phases. With the addition of B, (Moss + T2) binary and (Moss + T2 + Mo3Si) ternary eutectics emerge in Mo-10Si-(5, 10)B alloys. For Mo-10Si-15B alloy, primary Moss disappears and the microstructure is only composed of binary and ternary eutectics. With the increase of B content, the proportion and grain size of Moss decrease. The microhardness of alloys increases with the increase of B content due to the increasing intermetallics. The fracture toughness of alloys decreases obviously in single-edge notched three-point bending testing (SENB) and the fracture mode transforms from transgranular fracture to intergranular fracture because of the refinement of Moss. In the high-temperature oxidation test at 1250 °C, the oxidation weight loss of the alloys decreases with the addition of B due to the densification of the borosilicate layer.

Tailored ductility and strength for enhanced impact toughness of laser powder fusion built Alloy 718

Impact toughness of Alloy 718 built via laser powder bed fusion (LPBF) in as-built and thermally post-treated conditions were investigated. The effect of various stages in the thermal post-treatment, including stress relief, hot isostatic pressing, solution treatment, and aging on the microstructure, texture, ductility, hardness, and impact toughness were studied. The greatest impact toughness was found in the as-built Alloy 718 material, associated with the high ductility of the material. The ductility results were also inversely related to the hardness of the investigated materials. Where the material with the highest ductility had the lowest hardness etc. Anisotropy in the impact toughness behavior was present in the as-built and post-heat treated specimens, which was explained by the presence of texture in all of the investigated material. With the applied heat treatments, recrystallization occurred and the preferential crystal orientations were randomized, decreasing the texture. The thermal post-treating conditions rendered different types of microstructures, with various grain sizes. The carbide content remained the same for the three investigated thermal post-treating conditions.

Optimization of AlSi10MgMn Alloy Heat Treatment Process Based on Orthogonal Test and Grey Relational Analysis

By applying the orthogonal test, the T6 heat treatment test of the casting AlSi10MgMn alloy was carried out. Hardness, tensile strength, and elongation were selected as indicators for evaluating the toughness of alloy. Grey relational analysis was used to comprehensively evaluate the toughness of the alloy. Based on multiple linear regression, prediction models of hardness, tensile strength, elongation, and grey correlation were established. Through planning and solving, the optimal T6 heat treatment process parameters were obtained. According to the results of the metallographic structure analysis and the fracture SEM on the alloy after the T6 heat treatment, aging time, solution time, and solution temperature were identified as the most important factors affecting alloy hardness, tensile strength, and elongation, respectively. Through the application of grey relational analysis, the optimal T6 heat treatment process of an AlSi10MgMn alloy was obtained, namely 530 °C/1 h + 190 °C/6 h. Based on the solving of the prediction models, the optimal T6 heat treatment process and solution temperature of AlSi10MgMn alloy were obtained, namely 530 °C/3 h + 190 °C/8 h. Under these conditions, the hardness of the alloy was 96.9 HV, the tensile strength was 344.6 MPa, and the elongation was 6.1%. In contrast, the toughness of the alloy was better than that obtained by grey relational analysis. The T6 heat treatment refined the microstructure of the alloy, which resulted in a significant increase in fracture dimples.