Materials Science and Engineering: A最新文献

{"title":"Inhomogeneous microstructures, micropillar compression and thermomechanical properties of additive manufactured NiTi with Ni-loss compensation","authors":"Haizhou Lu ,&nbsp;Jinpeng Li ,&nbsp;Xinhao Zhuang ,&nbsp;Yong Yang ,&nbsp;Hongwei Ma ,&nbsp;Weisi Cai ,&nbsp;Chao Yang","doi":"10.1016/j.msea.2026.149890","DOIUrl":"10.1016/j.msea.2026.149890","url":null,"abstract":"<div><div>Ni-loss is an inevitable issue in the process of additive manufacturing for NiTi shape memory alloys (SMAs). Controlling the intensity of Ni-loss or compensating for the Ni-loss is crucial for achieving additive manufactured Ni-rich NiTi SMAs with the desired phase transformation temperatures and functional properties. In this work, the pre-alloyed NiTi powder is coated with nano-Ni particles evenly, compensating for the Ni-loss during the additive manufacturing for NiTi SMAs effectively. The formability of NiTi parts based on pre-alloyed NiTi powder coated with nano-Ni particles is acceptable, and the NiTi parts exhibits inhomogeneous microstructures. Specifically, NiTi B2 austenite matrix region occupied by uniform Ni₄Ti₃ and Ti₂Ni precipitates (Zone I), and NiTi B2 austenite matrix region with continuously Ti₂Ni precipitates along the grain boundaries (Zone II) are obtained. Compressive superelasticity test of cylindrical NiTi samples (φ3 × 6 mm) shows that an ultrahigh recovery strain of 6.22% and a large recovery rate of 86.4% in the 1st cycle, and a stable recovery strain of 5.01% and a corresponding recovery rate of 85.1% in the 10th cycle are achieved. Nanoindentation and micropillar (φ3 × 6 μm) compression results indicate that the zone I had a higher Young's modulus and nanohardness, and more stable compressive stress-strain curves compared to zone II. This is attributed to the effective strengthening provided by the coherent/semi-coherent interfaces of uniformly distributed precipitates in zone I, as opposed to the stress concentration and interface decohesion promoted by the semi-coherent/incoherent Ti₂Ni precipitates along grain boundaries in zone II. Furthermore, the semi-coherent or incoherent Ti₂Ni distributed along the grain boundaries in zone II tends to cause large stress concentration, thereby resulting in micropillar fracture in zone II during the compression process. Geometric phase analysis shows that due to the heterogeneous precipitates and inhomogeneous microstructures, a gradient strain field exists within the additive manufactured NiTi matrix, which could significantly enhance the superelasticity of the NiTi SMAs. These results provide a novel strategy for tailoring the microstructure of additive manufactured NiTi to yield superior functional properties.</div></div>","PeriodicalId":385,"journal":{"name":"Materials Science and Engineering: A","volume":"955 ","pages":"Article 149890"},"PeriodicalIF":7.0,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146171526","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Microstructure and properties of multiscale and multiphase ceramic particles reinforced Cu-Cr-Zr alloy prepared by turbulence shock homogeneous casting with B4C","authors":"Zhiwei Li ,&nbsp;Zuowen Zhu ,&nbsp;Junyu Lu ,&nbsp;Hanyu Cai ,&nbsp;Yanlin Huang ,&nbsp;Zhe Huang ,&nbsp;Jiaxin Peng ,&nbsp;Zhu Xiao ,&nbsp;Shen Gong","doi":"10.1016/j.msea.2026.149871","DOIUrl":"10.1016/j.msea.2026.149871","url":null,"abstract":"<div><div>Cu-Cr-Zr alloy exhibits high tensile strength and high electrical conductivity. To further enhance the tensile strength of Cu-Cr-Zr alloy and make it suitable for more fields, a Cu-Cr-Zr sample with multiscale and multiphase ceramic particles is prepared by turbulence shock homogeneous casting. B and C atoms from B₄C in-situ react with Cr and Zr atoms in the melt, the multiscale and multiphase ceramic particles such as Zr(B,C), Cr₇C₃, Zr₃C and ZrB₂ are formed, and the Cr precipitates are also formed in samples after heat treatment process. After homogenization at 950 °C for 2 h and 80% rolling deformation, followed by aging at 450 °C for 2 h, then second rolling deformation of 50% and low-temperature annealing at 200 °C for 2 h, Cu-1Cr-2Zr-0.5B₄C has the best properties with the tensile strength of 671 MPa and the electrical conductivity of 80.31 %IACS. Microstructure analysis shows that there are Zr(B,C), Zr₃C ceramic particles with irregular shapes and hexagonal ZrB₂ phases which has semi-coherent relationship with Cu in samples, meanwhile, nano-spherical Cr₇C₃ particles with average size of 200 nm and Cr precipitates approximately 4–5 nm in size are also observed in samples. Furthermore, dense dislocation structures are observed around ceramic particles. The excellent properties of the Cu-1Cr-2Zr-0.5B₄C sample are attributed to the effective hindering of dislocation movement by multiscale, multiphase ceramic particles and Cr precipitates. This study contributes to the advancement of high-performance Cu-Cr-Zr alloy.</div></div>","PeriodicalId":385,"journal":{"name":"Materials Science and Engineering: A","volume":"955 ","pages":"Article 149871"},"PeriodicalIF":7.0,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146171612","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Achieving ultra-high strength in copper-titanium alloys through multistage thermomechanical processing induced strengthening","authors":"Bofan Xu ,&nbsp;Qingjuan Wang ,&nbsp;Kuaishe Wang ,&nbsp;Wen Wang ,&nbsp;Hang Zhang ,&nbsp;Bin Gao ,&nbsp;Junpeng Sun ,&nbsp;Fei Wang","doi":"10.1016/j.msea.2026.149865","DOIUrl":"10.1016/j.msea.2026.149865","url":null,"abstract":"<div><div>This study systematically investigated the microstructure evolution and performance regulation mechanism of the environmentally friendly Cu-3Ti and Cu-3Ti-0.2Fe alloys during the multistage thermomechanical treatment. After process optimization, the tensile strength of Cu-3Ti and Cu-3Ti-0.2Fe alloys reached 1.24 GPa and 1.31 GPa, respectively, while the electrical conductivity remained at approximately 10.5 %IACS. The results showed that this multistage thermomechanical treatment could effectively induce the formation of high-density dislocations and nano-scale β′-Cu₄Ti precipitated phases, thereby generating a significant synergistic strengthening effect. Microscopic mechanism analysis indicated that the addition of trace Fe promoted the formation of deformation twinning by reducing the dislocation energy in the matrix. Moreover, due to the interaction between Fe and Ti, the lattice constant of Cu-3Ti-0.2Fe alloy remained lower than that of Cu-3Ti alloy after the multistage thermomechanical treatment. The strengthening mechanism analysis showed that in Cu-3Ti alloy, precipitation strengthening and dislocation strengthening jointly dominated the strength improvement, while in Cu-3Ti-0.2Fe alloy, precipitation strengthening was the main contributing mechanism. The developed multistage thermomechanical treatment strategy in this study effectively controlled the loss of electrical conductivity while achieving ultra-high strength, providing a feasible process path and theoretical basis for the development of a new generation of copper alloys with high performance and environmental friendliness.</div></div>","PeriodicalId":385,"journal":{"name":"Materials Science and Engineering: A","volume":"955 ","pages":"Article 149865"},"PeriodicalIF":7.0,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146171614","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Influence of local tensile direction on martensitic variant selection in the superelastic Ti-20Zr-12Nb-2Sn alloy","authors":"J.J. Gao ,&nbsp;Y.Q. Zhao ,&nbsp;F.X. Yin ,&nbsp;P. Castany ,&nbsp;T. Gloriant","doi":"10.1016/j.msea.2026.149864","DOIUrl":"10.1016/j.msea.2026.149864","url":null,"abstract":"<div><div>The superelastic Ti-20Zr-12Nb-2Sn (at.%) alloy after solution treatment at 700 °C for 30 min was investigated by cyclic tensile tests, <em>in situ</em> synchrotron X-ray diffraction (SXRD), and electron back-scattered diffraction (EBSD) after plastic deformation. The reversible stress-induced martensitic (SIM) α\" transformation was validated by <em>in situ</em> SXRD during loading/unloading, and the crystallographic orientation relationship between β phase and SIM α\" phase was investigated by EBSD from two specimens after 3 % and 7 % of deformation. In particular, martensitic variant selection is governed by the local tensile direction for individual grains. The maximum transformation strain varies with local tensile directions, but the selected martensitic variant consistently corresponds to the one exhibiting the highest transformation strain when the local tensile direction is near &lt;101&gt;_β or &lt;111&gt;_β directions. However, the activated variant deviates from this rule when the tensile direction is near &lt;100&gt;_β. This comprehensive study of the unexpected deviation in martensitic variant selection as a function of local tensile direction provides a better understanding of the superelastic performance of Ti-based alloys.</div></div>","PeriodicalId":385,"journal":{"name":"Materials Science and Engineering: A","volume":"955 ","pages":"Article 149864"},"PeriodicalIF":7.0,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146171634","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The mechanism of strength matching in governing the high-temperature creep of G115 steel welded joints","authors":"Xuan Wang ,&nbsp;Zhong-Yi Chen ,&nbsp;Wen-Jun Wang ,&nbsp;Yong-Qing Li ,&nbsp;Wen-Jia Yang","doi":"10.1016/j.msea.2026.149852","DOIUrl":"10.1016/j.msea.2026.149852","url":null,"abstract":"<div><div>This study systematically investigates the high-temperature creep behavior and microstructural evolution of G115 steel welded joints with varying strength matching ratios between weld metal and base metal under short-term, high-stress conditions. It is demonstrated that strength mismatch induces stress concentration in mechanically weaker regions, which accelerates initial strain accumulation and promotes the coarsening of Laves phase and M₂₃C₆ carbides. These effects collectively shorten the steady-state creep stage and significantly degrade creep life. The equal-strength matched joint (with a strength matching coefficient, <em>R∗</em> ≈ 1) exhibits the best performance among the weldments, showing 18.1 % and 135.1 % longer creep life than the overmatched and undermatched joints, respectively, under 650 °C and 180 MPa. Moreover, the benefit of strength matching becomes more pronounced under lower temperatures and stresses. Nevertheless, its performance remains inferior to the G115 steel due to microstructural heterogeneity in the heat-affected zone and the resulting microstress concentrations. A creep life prediction model incorporating <em>R∗</em> was developed, identifying <em>R∗</em> ≈ 1.05 as the optimal matching parameter under the present conditions. This model provides a theoretical basis for weld material selection and service life assessment of G115 steel welded structures.</div></div>","PeriodicalId":385,"journal":{"name":"Materials Science and Engineering: A","volume":"955 ","pages":"Article 149852"},"PeriodicalIF":7.0,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146171616","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The role of carbides in hydrogen permeation behaviour and mechanical degradation of aerospace 4340 and 300M steels","authors":"Johnny Adukwu Ebaika,&nbsp;Rajwinder Singh,&nbsp;Mamoun Medraj","doi":"10.1016/j.msea.2026.149892","DOIUrl":"10.1016/j.msea.2026.149892","url":null,"abstract":"<div><div>Martensitic structural steels are widely used in aerospace landing gears for their high strength to weight ratio but remain vulnerable to hydrogen embrittlement (HE). Hydrogen ingress occurs and leads to HE during electroplating or in corrosive environments which compromise component integrity even after post-plating baking. Consequently, there is a growing need to select steels with microstructure that restrict hydrogen uptake and improve HE resistance. This study evaluates HE responses of 4340 and 300M using electrochemical hydrogen permeation and shear punch tests (SPTs). This study shows that 4340 have higher hydrogen diffusivity and permeability than 300M, mainly due to differences in precipitates, particularly (Cr, Mn) carbides in 4340 and (Mo, Si) carbides in 300M. At low hydrogen permeation, 300M exhibits superior HE resistance due to the high trapping capacity of hydrogen by (Mo, Si) carbides, which limits hydrogen ingress and results in minimal shear strength degradation compared to 4340. Under high hydrogen exposure, saturation of traps with hydrogen in 300M causes abrupt shear strength loss, while 4340 experiences linear drop in strength. Fractographic analysis reveals mixed-mode brittle fracture in 4340 at all hydrogen levels, whereas 300M maintains predominantly cleavage fracture even under high hydrogen exposure. Strong hydrogen trapping sites and improved matrix strengthening by (Mo, Si) carbides reduce HE degradation in 300M. These results provide valuable insights for alloy design and material selection of HE-resistant martensitic steels in demanding aerospace applications such as landing gears.</div></div>","PeriodicalId":385,"journal":{"name":"Materials Science and Engineering: A","volume":"955 ","pages":"Article 149892"},"PeriodicalIF":7.0,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146171636","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Optimization of microstructure and properties in high-strength coherent BCC/B2 multi-principal element alloys via laser directed energy deposition","authors":"Xuanhong Cai ,&nbsp;Liufei Huang ,&nbsp;Congcong Ren ,&nbsp;Ben Niu ,&nbsp;Yancheng Li ,&nbsp;Qing Wang ,&nbsp;Jinfeng Li","doi":"10.1016/j.msea.2026.149904","DOIUrl":"10.1016/j.msea.2026.149904","url":null,"abstract":"<div><div>Body-centered-cubic (BCC)-based multi-principal element alloys (MPEAs) are considered promising materials due to their excellent mechanical properties, particularly at elevated temperatures. However, their limited processability and high melting points impose significant challenges for the fabrication of load-bearing components by conventional casting. This work demonstrates the successful development of a novel BCC-based MPEA of Al₂Ti₄Zr₄Nb₃Ta₃ through laser directed energy deposition (LDED). The additive manufactured cylindrical components exhibit excellent formability without cracks and distortion. The LDED processing promotes the in-situ microstructural optimization of the alloy, forming a homogeneous coherent BCC/B2 microstructure with cuboidal BCC nanoparticles precipitated in the B2 matrix, and achieving ultra-high yield strength of 2013 MPa at room temperature. The excellent strength is primarily attributed to the precipitation strengthening of cuboidal BCC nanoparticles and solid solution strengthening of alloying elements. Moreover, the LDED alloy exhibits a yield strength of 1380 MPa at 873 K and retains a yield strength of 290 MPa even at 1273 K. This work provides feasible avenue for additive manufacturing of BCC-based MPEAs, thereby facilitating their industrial applications.</div></div>","PeriodicalId":385,"journal":{"name":"Materials Science and Engineering: A","volume":"956 ","pages":"Article 149904"},"PeriodicalIF":7.0,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146147404","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Influence of single- and double-step solution and aging treatments on the microstructure, texture, and mechanical properties of cold-rolled Al–Cu–Li alloy sheets (Cu/Li ratios 2 and 4) produced via squeeze casting","authors":"S. Manojkumar,&nbsp;Yogesh Singh,&nbsp;K.K. Mehta","doi":"10.1016/j.msea.2026.149828","DOIUrl":"10.1016/j.msea.2026.149828","url":null,"abstract":"<div><div>Squeeze-cast Al–Cu–Li alloys, SC1 (Cu/Li ≈ 2, Li ≈ 1.28 wt%) and SC2 (Cu/Li ≈ 4, Li ≈ 0.53 wt%), studied in three heat-treatment conditions: H1 (single-step solution → quenching → double-aging), H2 (double-step solution → quenching → double aging), and H3 (double-step solution → quenching → single aging). Cold rolling of SC1 developed pronounced crystallographic textures, strongly influenced by the Cu/Li ratio and Li-content. Nearly double the Li in SC1 led to a fourfold increase in texture intensity compared to SC2, mainly from strong Copper <span><math><mrow><mo>(</mo><mrow><mrow><mo>{</mo><mn>112</mn><mo>}</mo></mrow><mspace></mspace><mrow><mo>⟨</mo><mn>111</mn><mo>⟩</mo></mrow></mrow><mo>)</mo></mrow></math></span> component. Heat treatment markedly influenced the strength–ductility trade-off. In SC1, the H1 condition achieved nearly twice the strength of H3 but incurred a twofold reduction in ductility, attributed to a higher fraction of T1 (Al₂CuLi) precipitates formed during double aging. SC2 displayed superior ductility but limited strength, particularly under H3 treatment. Mechanical performance was governed by the combined effects of solution treatment, controlling grain size and texture, and aging treatment, regulating precipitation. The superior strength of SC1 in H1 condition arose from the synergistic effect of refined grains with strong Cube texture and enhanced T1 precipitation. Conversely, low Li content in SC2 restricted T1 precipitation, limiting strengthening. H3 triggers dislocation looping and serrations in stress–strain curves via T2 (Al₆CuLi₃) precipitates, while H1 (SC1) suppresses serrations by depleting Cu and Li through high T1 precipitation. Constitutive modeling using the Voce's-relationship and KM-model showed excellent agreement with experiments, providing a robust framework for optimizing heat-treatment routes for Al–Cu–Li alloys.</div></div>","PeriodicalId":385,"journal":{"name":"Materials Science and Engineering: A","volume":"955 ","pages":"Article 149828"},"PeriodicalIF":7.0,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146077035","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Achieving strength-plasticity synergy via non-monotonic gradient structured in Zr-based bulk metallic glasses","authors":"Xiaoqiang Fu ,&nbsp;Chunyan Li ,&nbsp;Zhenxiang Zhao ,&nbsp;Chaoqun Pei ,&nbsp;Xuesong Li ,&nbsp;Zhengrui Su ,&nbsp;Haiqun Wang ,&nbsp;Shengzhong Kou ,&nbsp;Baoan Sun ,&nbsp;Yuchen Mao","doi":"10.1016/j.msea.2026.149907","DOIUrl":"10.1016/j.msea.2026.149907","url":null,"abstract":"<div><div>This work proposes a strategy for rapidly constructing non-monotonic gradient structures in Zr-based bulk metallic glasses (BMGs) to overcome their limited plasticity. This method relies on the dynamic coupling of temperature and stress fields. Specifically, the combination of elastic stress loading (<em>δ</em> = <em>X</em>·<em>δ</em>_y, <em>X</em> = 30%, 40%, 50%) under thermal conditions (<em>T</em> = 423 K) and cryogenic treatment (<em>T</em> = 77 K) enables the redistribution of residual stress and free volume. The structure was systematically characterized via nanoindentation, differential scanning calorimetry (DSC), atomic force microscopy (AFM), X-ray photoelectron spectroscopy (XPS), and Vickers hardness profiling. During the thermoelastic loading stage, the temperature gradient induces distinct relaxation behaviors between the interior and exterior, leading to a gradient distribution of free volume. Simultaneously, under the coupling effect of stress, a residual stress gradient distribution is formed. Furthermore, this gradient structure is enhanced during cryogenic treatment due to the asymmetry between tensile and compressive stresses, resulting in a macroscopically controllable non-monotonic gradient structure. This structure alters the linear propagation path of shear bands and generates numerous multiple shear bands in the gradient transition regions, effectively prolonging the uniform strain duration. Consequently, a yield strength of 1720 MPa and a compressive plasticity of 18.5% were achieved. This work provides new insights into the rapid construction of gradient structures and the mechanical enhancement of BMGs.</div></div>","PeriodicalId":385,"journal":{"name":"Materials Science and Engineering: A","volume":"956 ","pages":"Article 149907"},"PeriodicalIF":7.0,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146172673","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Constructing heterogeneous grain structure in Al–La–Sc alloy to overcome high-temperature softening","authors":"Xinkui Zhang ,&nbsp;Yongji Chen ,&nbsp;Liejun Li ,&nbsp;Zhuoran Li ,&nbsp;Jixiang Gao ,&nbsp;Zhengwu Peng","doi":"10.1016/j.msea.2026.149874","DOIUrl":"10.1016/j.msea.2026.149874","url":null,"abstract":"<div><div>Heterogenous structure design strategy is commonly employed to fabricate alloy with excellent mechanical properties at room temperature, but it's high-temperature performance is unknown. Here, a heterogenous grain structure was employed to overcome the high-temperature softening of fine grain in Al–La–Sc alloy produced by hot extrusion process, realizing synergistic improvement in room- and high-temperature strength. The heterogenous structure is characterized by fibrous coarse grain embedded in equiaxed fine grain, which inherit from the microstructure of the cast counterpart and the pinning effect of Al₃Sc particles. The fine grain structure and evenly-distributed Al₃Sc particles enhance the room temperature strength of the alloy via grain refinement and Orowan strengthening mechanisms, respectively. The coarse grain increased the high-temperature strength via inhibiting the deformation of fine grain, while the micron Al₁₁La₃ and nano-scale Al₃Sc intermetallics retarded dislocation and grain boundary movement to further enhance the strength. This work provided a novel microstructure design strategy to fabricate heat resistance aluminum alloys, expanding the application of heterogenous grain structure.</div></div>","PeriodicalId":385,"journal":{"name":"Materials Science and Engineering: A","volume":"956 ","pages":"Article 149874"},"PeriodicalIF":7.0,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146172765","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}