Materials Science and Engineering: A最新文献

{"title":"Fracture behavior in inhomogeneous brazed joints: Microstructural effects on peeling crack propagation","authors":"Yu Cao,&nbsp;Guo-Yan Zhou,&nbsp;Peng-Peng Liao,&nbsp;Shan-Tung Tu","doi":"10.1016/j.msea.2026.149889","DOIUrl":"10.1016/j.msea.2026.149889","url":null,"abstract":"<div><div>This study elucidates the mechanisms of crack initiation and propagation in complex brazed joints subjected to peeling fractures. A multi-parameter evaluation criterion for assessing peeling crack propagation has been developed within the microstructural framework. Controllable inhomogeneous joints were fabricated, and peeling tests were conducted. Fractographic and cross-sectional morphologies were analyzed to identify the fracture path and mode. The microstructural evolution of grain paths during crack initiation, deflection, and stable propagation was monitored through advanced characterization techniques. A comprehensive evaluation of the elastic modulus (<em>E</em>), Schmid factor (<em>m</em>), geometric compatibility factor (<em>m</em>′), twist angle (<em>α</em>), tilt angle (<em>β</em>), and grain boundary properties resulted in the development of a criterion combing grain characteristics and geometrical compatibility for slip transfer. The results indicate that cracks preferentially initiate in grains with high <em>m</em> and low <em>E</em>, propagating along microstructural channels characterized by <em>m</em> &gt; 0.3, <em>α</em> &lt; 45°, and <em>m</em>′ &lt; 0.3.</div></div>","PeriodicalId":385,"journal":{"name":"Materials Science and Engineering: A","volume":"956 ","pages":"Article 149889"},"PeriodicalIF":7.0,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146147400","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":"A machine learning framework augmented by generative models for accelerated design of refractory high-entropy alloys with superior strength-ductility synergy","authors":"Liang Zhu,&nbsp;Jiakun Wang,&nbsp;Minghang Zhou,&nbsp;Lingti Kong,&nbsp;Jinfu Li","doi":"10.1016/j.msea.2026.149938","DOIUrl":"10.1016/j.msea.2026.149938","url":null,"abstract":"<div><div>Achieving a balance between strength and ductility at room temperature remains a grand challenge in developing body-centered cubic (BCC) refractory high-entropy alloys (RHEAs). Facing the vast compositional design space, we propose an alloy design framework, GAMP, combining a Generative Adversarial Network (GAN) with machine learning (ML) prediction models to accelerate the screening of potential alloy compositions. Unlike common inverse design or image-based approaches, the GAN in this work functions as a generator within a forward search loop, specifically capturing the latent distribution of existing alloys to propose high-potential new candidates. Among various models, eXtreme Gradient Boosting (XGBoost) was identified as the most accurate for predicting ultimate tensile strength (UTS) and elongation (El) to failure. A designed alloy, Al_9.6Ti_38.0Nb_20.5Hf_16.5V_15.4, was experimentally validated to exhibit a UTS of 1058.1 MPa and an El of 18.5% at room temperature. Interpretability analysis further revealed that shear modulus local mismatch (<em>G</em>_LM) and atomic size difference (<em>δ</em>) are the dominant descriptors for UTS, while enthalpy of mixing (Δ<em>H</em>_mix) is the key indicator for El. Microstructural analysis revealed that the superior strength-ductility synergy resulted from the activation of multiple deformation mechanisms, in which the formation of kink bands is a key factor enabling the excellent room-temperature ductility. This study presents an efficient framework for designing advanced alloys with complex property requirements.</div></div>","PeriodicalId":385,"journal":{"name":"Materials Science and Engineering: A","volume":"956 ","pages":"Article 149938"},"PeriodicalIF":7.0,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147403397","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":"Hot deformation behavior and recrystallization mechanism of a novel Ni-based superalloy GH4780","authors":"Yang Liu ,&nbsp;Xingfei Xie ,&nbsp;Tianhao Feng ,&nbsp;Xing Su ,&nbsp;Jinglong Qu ,&nbsp;Jinhui Du ,&nbsp;Lilong Zhu","doi":"10.1016/j.msea.2026.149836","DOIUrl":"10.1016/j.msea.2026.149836","url":null,"abstract":"<div><div>Ni-based superalloys serve as critical high-temperature components in advanced aerospace engines, where precise prediction of hot deformation behavior and microstructural evolution is essential for manufacturing process optimization. This study systematically investigates the hot deformation characteristics and dynamic recrystallization (DRX) mechanisms of a novel GH4780 superalloy through thermal compression experiments spanning 1030–1120 °C and strain rates of 0.001–1 s⁻¹. A corrected constitutive model integrating friction, thermal, and strain effects was developed, demonstrating excellent predictability of flow behavior across the tested conditions. Microstructural analysis via electron backscatter diffraction (EBSD) and transmission electron microscopy (TEM) reveals that discontinuous dynamic recrystallization (DDRX) dominates the softening process, while twin-induced dynamic recrystallization (TDRX) significantly enhances nucleation at grain boundaries. Continuous dynamic recrystallization (CDRX) functions as a supplementary mechanism active particularly under low-temperature and high-strain-rate conditions. The activation energy (<em>Q</em>) for hot deformation ranges from 427.70 to 476.42 kJ mol⁻¹, with higher values corresponding to enhanced degree of DRX, typically presenting as larger recrystallized areas or grain structures exhibiting both uniform size and homogeneous distribution. These findings provide fundamental insights into the multi-mechanism DRX behavior of GH4780 superalloy, establishing a theoretical basis for optimizing its thermo-mechanical processing parameters.</div></div>","PeriodicalId":385,"journal":{"name":"Materials Science and Engineering: A","volume":"956 ","pages":"Article 149836"},"PeriodicalIF":7.0,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147403399","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":"Additive manufacturing of stainless steel with controllable phase compositions: from ferrite, duplex phase to austenite stainless steel","authors":"Yujin Nie ,&nbsp;Liuwei Zheng ,&nbsp;Fei Yang ,&nbsp;Lixin Meng ,&nbsp;Quanxin Shi ,&nbsp;Jinyao Ma ,&nbsp;Wei Liang","doi":"10.1016/j.msea.2026.149772","DOIUrl":"10.1016/j.msea.2026.149772","url":null,"abstract":"<div><div>The microstructure is typically a relatively fixed phase with limited tunability when fabricated by Laser powder bed fusion (LPBF) using fixed-composition powders. This limitation hinders the flexible preparation of diverse microstructures. To achieve continuous control of microstructures from pure ferrite to pure austenite and overcome the challenges in fabricating duplex stainless steels, this study innovatively proposes a novel strategy based on in-situ laser alloying of heterogeneous powders. By adjusting the mixing ratio of commonly available 430 and 316L powders, stainless steel with controllable ferrite/austenite phase ratios was successfully fabricated, enabling the direct production of duplex stainless steels. The results demonstrate that under different powder ratios, the as-built alloys consist solely of ferrite and/or austenite due to the extremely rapid cooling rate, which suppresses elemental diffusion and prevents nucleation and growth for secondary phases. With increasing mass percentage of 316L powder, the volume fraction of austenite gradually increased from 0% to 100%, while the coexistence of dual phases significantly refined grain size. The as-built alloys exhibit higher ultimate tensile strength and excellent elongation, all demonstrating superior comprehensive mechanical properties compared to additively manufactured stainless steels of the same type. Ferrite achieves remarkable strengthening through high-density dislocations, whereas austenite enhances plasticity synergistically via the formation of stacking faults, nano-twins, dislocations, and their cellular structures. The TRIP effect occurring during deformation not only hindered dislocation motion but also effectively promoted stress redistribution, further optimizing the strength-ductility balance. This research provides an innovative solution for the integrated \"process-microstructure-properties\" design of additively manufactured stainless steels.</div></div>","PeriodicalId":385,"journal":{"name":"Materials Science and Engineering: A","volume":"955 ","pages":"Article 149772"},"PeriodicalIF":7.0,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146171523","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":"In-situ fabrication of NiTiTa alloys by laser-directed energy deposition: Strength-toughness synergy mechanisms","authors":"Yan Wu,&nbsp;Guangyi Ma,&nbsp;Xinhui Li,&nbsp;Tengda Di,&nbsp;Bin Wu,&nbsp;Yunlong Li,&nbsp;Fangyong Niu,&nbsp;Dongjiang Wu,&nbsp;Danlei Zhao","doi":"10.1016/j.msea.2026.149860","DOIUrl":"10.1016/j.msea.2026.149860","url":null,"abstract":"<div><div>While operating temperature demands for aerospace actuators continue to rise, tantalum (Ta) addition has emerged as a promising approach to developing high-temperature NiTi shape memory alloys (SMAs). However, the high melting point of Ta causes severe elemental segregation in NiTiTa alloys with conventional fabrication methods due to insufficient cooling rates. In this study, NiTiTa SMAs were successfully fabricated via in-situ alloying using laser-directed energy deposition (L-DED), which leverages its high cooling rate to achieve a homogeneous microstructure. This study systematically investigates the influence of Ta content (0–9 at.%) on the microstructure and properties of NiTi alloys. The as-deposited NiTiTa alloys exhibited a eutectic microstructure composed of a B19′ martensitic matrix, (Ti, Ta)₂Ni precipitates, and β-Ta phases. The incorporation of Ta resulted in substantial grain refinement, with a reduction of up to 86 %, and increased the ultimate tensile strength by 27 % via solid solution strengthening, achieving a strength-toughness synergy. Futheremore, Ta addition systematically elevated the phase transformation temperatures, and the martensite start temperature (<em>M</em>_<em>s</em>) reached approximately 80 °C in the high Ta content alloy, primarily due to the reduction in matrix Ni content, along with the martensite stabilizing effects of Ta solute atoms and high-density dislocations. This work demonstrates that L-DED is an effective technique for in-situ fabricating homogeneous NiTiTa SMAs with refined microstructures, enhanced strength, and tunable transformation temperatures, providing new insights for developing high-performance NiTi-based SMAs.</div></div>","PeriodicalId":385,"journal":{"name":"Materials Science and Engineering: A","volume":"955 ","pages":"Article 149860"},"PeriodicalIF":7.0,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146171528","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":"Anisotropic high-temperature embrittlement of laser powder bed fused Al-Fe-Cr alloy containing Si element","authors":"Yifan Xu ,&nbsp;Dasom Kim ,&nbsp;Koki Minamihama ,&nbsp;Junji Umeda ,&nbsp;Yuhki Tsukada ,&nbsp;Naoki Takata","doi":"10.1016/j.msea.2026.149875","DOIUrl":"10.1016/j.msea.2026.149875","url":null,"abstract":"<div><div>This study focused on an Al-Fe-Cr alloy system with a certain amount of Si (a major impurity in Al alloys) as a model for high-temperature alloys with an industrially produced composition suitable for laser-beam powder bed fusion (PBF-LB) processing. The phase equilibria and solidification sequence in the experimental alloy composition of Al-2.5Fe-2Cr-0.5Si (mass%) were analyzed via thermodynamic calculations. The gas-atomized alloy powder exhibited excellent processability in the PBF-LB process, resulting in the manufacture of fully dense alloy specimens with relative densities exceeding 99%. The PBF-LB-fabricated Al-Fe-Cr-Si alloy exhibited a melt-pool structure formed through repeated local melting and rapid solidification during scanning laser irradiation. Several grains containing high-density low-angle boundaries (sub-boundaries) were elongated along the building direction (BD) in the α-Al matrix with a crystallographic texture of &lt;110&gt;//BD. The relatively coarsened Al₁₁Cr₂ phases were localized around the melt pool boundaries, whereas numerous nanosized particles of the Al₆Fe metastable phase containing Si and Cr were dispersed within the melt pool interior. Consequently, the strength of the Al-Fe-Cr-Si alloy specimen was considerably higher than that of the Al-Fe binary alloys. However, the Al-Fe-Cr-Si alloy specimen exhibited significant ductility loss only in the direction perpendicular to the BD upon elevating the test temperature to 300 °C. The high-temperature embrittlement may be attributed to preferential fracture at many precipitates of the Si-rich intermetallic phase (presumably brittle) formed at the boundaries of the α-Al grains elongated along the BD. These results provide new insights into the design of alloy composition, including impurity elements, for controlling the high-temperature mechanical performance of Al-Fe multi-elemental alloys suitable for PBF-LB processing.</div></div>","PeriodicalId":385,"journal":{"name":"Materials Science and Engineering: A","volume":"955 ","pages":"Article 149875"},"PeriodicalIF":7.0,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146171618","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":"Toughening and deformation mechanisms of dual heterogeneous SiCp/2024Al composites","authors":"Kan Liu ,&nbsp;Yunpeng Cai ,&nbsp;Aoke Jiang ,&nbsp;Lichaoran Guan ,&nbsp;Yiwei Dong ,&nbsp;Ruian Wang ,&nbsp;Yishi Su ,&nbsp;Qiubao Ouyang ,&nbsp;Di Zhang","doi":"10.1016/j.msea.2026.149840","DOIUrl":"10.1016/j.msea.2026.149840","url":null,"abstract":"<div><div>The deformation mechanism of heterogeneous Al matrix composites is yet unclear. Here, dual heterogeneous SiCp/2024Al composites integrating bimodal dispersoids within heterogeneous nano-laminated matrix were fabricated via powder metallurgy. Superior mechanical properties of 97.7 GPa, 713.5 MPa and 6.5 % respectively in modulus, tensile strength and elongation are obtained, with ductility elevated by 81 % by sacrificing only 3 % strength, leading to a toughness of 41.5 MJ/m³ that is 77 % higher than uniform ultrafine-grained (UFG) counterparts. Dislocation strengthening is the primary strengthening mechanism due to the enhanced dislocation storage. Deformation rate-controlled mechanisms were studied by strain rate jumping tests. Grain boundary-dislocation interaction is identified as the deformation mechanism of UFG counterparts, due to the increased dislocation absorption into grain boundaries. Dual heterogeneous composites exhibit lower strain rate sensitivity and higher activation volumes, whose deformation is mediated by forest dislocation cutting despite having only 594 nm in average matrix grain size. The transition in deformation mechanisms originates from hetero-interface induced extra geometrically necessary dislocation multiplication and intersection, facilitating an improved strain hardening. This work may provide insight into architecture induced toughening for metal matrix composites.</div></div>","PeriodicalId":385,"journal":{"name":"Materials Science and Engineering: A","volume":"955 ","pages":"Article 149840"},"PeriodicalIF":7.0,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146171619","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 effect of standard heat treatments and process conditions on the fatigue performance of wire arc additively manufactured Ti-6Al-4V","authors":"Jackson Leigh Smith ,&nbsp;Alexander Medvedev ,&nbsp;Edward Lui ,&nbsp;Jiayu Ye ,&nbsp;Philip Pille ,&nbsp;Stephen Sun ,&nbsp;Michael Bermingham ,&nbsp;Daniel Fisher ,&nbsp;Jisheng Ma ,&nbsp;Martin Leary ,&nbsp;Qianchu Liu ,&nbsp;Milan Brandt","doi":"10.1016/j.msea.2026.149833","DOIUrl":"10.1016/j.msea.2026.149833","url":null,"abstract":"<div><div>Wire arc additive manufacturing (WAAM) offers a cost-effective route for producing large, customised Ti-6Al-4V airframe components, yet the influence of heat treatments and process conditions on fatigue life remains unclear. This study examines how fatigue performance is shaped by standard additive manufacturing heat treatments, including stress relieving (SR), solution treating and aging (STA), hot isostatic pressing (HIP) and annealing, and key process parameters, including nozzle to workpiece distance and shielding atmosphere. STA refined the microstructure and increased strength but produced little improvement in fatigue life, while SR had negligible effects due to already low residual stresses in the as-machined state. In contrast, annealed specimens built with a more optimal nozzle to workpiece distance showed improved fatigue life despite lower yield strength, driven by high relative density (&gt;99.99 percent) and greater ductility. HIP produced full densification and the best fatigue performance. Poor shielding reduced relative density and degraded fatigue resistance, despite strengthening from diffused oxygen. Fractography revealed that fatigue cracks initiated at sharp notches around clustered gas pores, where high stress concentrations accelerated crack coalescence and ligament rupture. Overall, the results demonstrate that clustered porosity, not microstructural refinement or strength alone, governs fatigue life in WAAM Ti-6Al-4V, highlighting the need to control pore nucleation and growth for reliable aerospace use.</div></div>","PeriodicalId":385,"journal":{"name":"Materials Science and Engineering: A","volume":"955 ","pages":"Article 149833"},"PeriodicalIF":7.0,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146171622","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 mechanical properties of 2219 aluminum alloy fabricated by dual ultrasonic impact treatment-assisted wire-arc directed energy deposition","authors":"Dongqing Yang ,&nbsp;Jun Feng ,&nbsp;Zehui Qin ,&nbsp;Gaige Chang ,&nbsp;Lei Wang ,&nbsp;Yong Huang ,&nbsp;Xiaopeng Li","doi":"10.1016/j.msea.2026.149885","DOIUrl":"10.1016/j.msea.2026.149885","url":null,"abstract":"<div><div>To address issues such as microstructural inhomogeneity, coarse grains, and porosity defects in 2219 aluminum alloy fabricated by wire-arc directed energy deposition (WA-DED), this study introduces dual ultrasonic impact treatment (D-UIT) into the WA-DED process. By establishing a D-UIT-assisted WA-DED system, the effects of D-UIT on the microstructure and mechanical properties of single-bead multi-layer deposited samples were investigated. Results indicate that D-UIT notably refines the grain structure, reducing the average grain size to a range of 62.08–71.69 μm. It eliminates coarse columnar crystals and strong texture, leading to a significant improvement in microstructural homogeneity, with a 65% reduction in the maximum pole density value. Meanwhile, the average pore volume and porosity of the D-UIT-treated WA-DED samples decreased by 93.3% and 91.8%, respectively. D-UIT also increased the microhardness by 24%, and the tensile strength improved by 15.2% in the horizontal direction and 9.0% in the vertical direction. These enhancements are primarily attributed to the combined effects of grain refinement strengthening, defect control, and texture weakening induced by D-UIT. Therefore, D-UIT-assisted WA-DED provides a novel approach for producing high-performance metal components and holds broad application potential.</div></div>","PeriodicalId":385,"journal":{"name":"Materials Science and Engineering: A","volume":"955 ","pages":"Article 149885"},"PeriodicalIF":7.0,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146171623","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":"Enhanced strength and ductility in aluminum alloys produced by laser powder bed fusion: Tunable nano-precipitates effect via copper addition","authors":"Hai Hu ,&nbsp;Bin Yin ,&nbsp;Lei Qin ,&nbsp;Fei Xu ,&nbsp;Huan Yang ,&nbsp;Cheng Deng ,&nbsp;Shengfeng Zhou","doi":"10.1016/j.msea.2026.149870","DOIUrl":"10.1016/j.msea.2026.149870","url":null,"abstract":"<div><div>To enhance the limited strength of as-printed AlMgErZrSc alloys, cost-effective Cu was introduced into the AlMgErZrSc system via laser powder bed fusion (LPBF). A systematic investigation was conducted to study the effect of Cu content (1, 3, 5, 7 wt%) on microstructure and mechanical properties. The results demonstrate that increasing Cu content from 0 to 7 wt% can enlarge the width of the fine equiaxed zone (FEZ) at the molten pool boundaries from 1.5 ± 0.17 μm to 13.3 ± 0.93 μm-a ninefold enhancement. This microstructural evolution is driven by Cu-induced constitutional supercooling and heterogeneous nucleation of Al₃(Sc,Zr) precipitates, which synergistically facilitate the formation of fine equiaxed grains. At Cu concentrations ≥3 wt%, the eutectic reaction is activated, stabilizing the precipitation of S-Al₂CuMg. This process consumes Mg, suppressing β-Mg₂Si formation and creating competitive precipitation dynamics. The nanoscale S-Al₂CuMg and β-Mg₂Si distributed at the grain boundaries of α-Al matrix generate a pinning effect, effectively impeding dislocation movement and strengthening the α-Al matrix. However, adding excessive Cu (7 wt%) can lead to high dislocation density (∼1.41 × 10¹⁵ m⁻²) and coarse secondary S-Al₂CuMg, thereby inducing stress concentration and a reduction in ductility. Therefore, the AlMgErZrSc-5Cu alloy exhibits an enhanced ultimate tensile strength of 534 ± 8 MPa and elongation of 8.6 ± 0.9%. The Cu-induced strengthening mechanisms include: (<em>i</em>) solid-solution strengthening of Cu, (<em>ii</em>) grain-boundary strengthening of α-Al, (<em>iii</em>) dislocation strengthening, and (<em>iv</em>) precipitation strengthening from L1₂-Al₃(Sc,Zr)/S-Al₂CuMg/β-Mg₂Si nano-phases.</div></div>","PeriodicalId":385,"journal":{"name":"Materials Science and Engineering: A","volume":"955 ","pages":"Article 149870"},"PeriodicalIF":7.0,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146171639","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}