Materials Science and Engineering: A最新文献

{"title":"A high-strength and ductile titanium alloy fabricated by metal injection molding","authors":"Haiyue Zhang ,&nbsp;Yifan Nie ,&nbsp;Chang Liu ,&nbsp;Muhammad Dilawer Hayat ,&nbsp;Jinghao Wei ,&nbsp;Gang Chen ,&nbsp;Lu Li ,&nbsp;Mingli Qin ,&nbsp;Junwen Wu ,&nbsp;Minglu Zhu ,&nbsp;Xuanhui Qu","doi":"10.1016/j.msea.2025.148562","DOIUrl":"10.1016/j.msea.2025.148562","url":null,"abstract":"<div><div>This study presents a high-strength and ductile titanium (Ti) alloy fabricated by introducing 0.5 wt% graphite into a Ti-Al-Mo-V-Cr-based alloy (termed as ‘A-0.5C’) using metal injection molding (MIM), with the comparison of non-graphite doped alloy (termed as ‘A’). The microstructural analysis shows numerous TiC precipitates distributed along grain boundaries, forming a coherent interface with the Ti matrix. Furthermore, carbon doping promotes a multi-stage densification mechanism, efficiently reducing residual porosity and further enhancing final ductility. The A-0.5C specimen exhibited an ultimate tensile strength of 1277.8 ± 5.4 MPa and a total elongation of 11.7 ± 0.3 %. The strengthening effects arise from solid solution, grain refinement, and secondary phase. In addition, the coherent interface between the TiC precipitate and matrix helps to relieve stress concentration, and resist crack initiation and propagation, benefiting ductility. Our developed Ti alloy fabricated by MIM surpasses the strength of 1100 MPa, achieving the high-strength level while maintaining excellent ductility. This study paves the way for high-performance Ti alloys in advanced engineering applications.</div></div>","PeriodicalId":385,"journal":{"name":"Materials Science and Engineering: A","volume":"940 ","pages":"Article 148562"},"PeriodicalIF":6.1,"publicationDate":"2025-05-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144166875","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":"Impact of hydrogen-assisted cracking on the mechanical properties of 316L stainless steel produced by selective laser melting using an in-situ small punch test","authors":"Van Hung Dao ,&nbsp;Kee Bong Yoon ,&nbsp;Hee Soo Yun ,&nbsp;Hyusang Kwon ,&nbsp;Kyung-Oh Bae ,&nbsp;Seung Hoon Nahm","doi":"10.1016/j.msea.2025.148557","DOIUrl":"10.1016/j.msea.2025.148557","url":null,"abstract":"<div><div>This study investigates the impact of hydrogen-assisted cracking on the mechanical properties of 316L stainless steel (SS316L) produced by selective laser melting (SLM) using a small punch (SP) test. The relationships between the process parameters, specifically the scan speed, laser power, energy density, and strength characteristics of SS316L are explored, with a particular focus on the effect of hydrogen precharging. Experimental results demonstrate that increasing the scan speed and laser power improves the maximal peak load (P_m) and fracture displacement (δ_f) up to an optimal range. This improvement is attributed to enhanced microstructural properties, including better fusion and a reduction in grain size, which results in more uniform grain structures and contributes to higher mechanical strength. However, beyond this optimal range, the mechanical performance diminishes owing to the reduced energy density, leading to poorer microstructural integrity. These findings suggest that the optimal SLM parameters for achieving superior mechanical properties in SS316L lie within a specific range of scan speeds and energy densities. Hydrogen precharging, on the other hand, leads to a significant degradation in mechanical properties, with reductions in both P_m and δ_f compared to uncharged specimens. This degradation suggests the occurrence of hydrogen-enhanced localized plasticity (HELP). Geometrically necessary dislocations (GNDs) and twin density measurements are obtained from the stretched regions of the interrupted SP specimens. These measurements provide insights into the underlying hydrogen-induced damage mechanisms by which hydrogen precharging exacerbates material degradation.</div></div>","PeriodicalId":385,"journal":{"name":"Materials Science and Engineering: A","volume":"940 ","pages":"Article 148557"},"PeriodicalIF":6.1,"publicationDate":"2025-05-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144154732","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 dynamic compression behavior of Cu-Cr-W alloy under different impact rates","authors":"Zengye Ning ,&nbsp;Xiuqing Li ,&nbsp;Qingxia Yang ,&nbsp;Jie Wu ,&nbsp;Tianyao Guo ,&nbsp;Xinyu Zhang ,&nbsp;Lewei Lu ,&nbsp;Haiyang Pei ,&nbsp;Huijie Liu ,&nbsp;Dan Jia ,&nbsp;Longwei Zhou","doi":"10.1016/j.msea.2025.148582","DOIUrl":"10.1016/j.msea.2025.148582","url":null,"abstract":"<div><div>This study reports on the preparation of Cu-Cr-W alloys with varying Cr contents achieved through mechanical alloying and spark plasma sintering methods. Field emission scanning electron microscopy and transmission electron microscopy were employed to carefully observe and analyze the micro-morphological features, elemental composition, and microstructural details of the Cu-Cr-W composite powders as well as the alloy samples. The dynamic compression behaviors of Cu-Cr-W alloys under different impact rates were investigated using a Hopkinson pressure bar device. Electron backscatter diffraction was utilized to comprehensively assess the phase makeup, characteristics of grain boundaries, geometrically essential dislocation density, and inverse pole figures of the Cu-Cr-W alloy specimens after dynamic compression. Experimental results demonstrate that during the sintering process, Cr can react with the W phase to form a Cr_0.5W_0.5 solid solution. Additionally, the addition of Cr improves the uniformity of the dispersion of W particles in the Cu matrix. As the Cr content rises, the ability of the Cu-Cr-W alloy to resist dynamic compression improves significantly. This is mainly attributed to the synergistic effect of multiple strengthening mechanisms generated by Cr within the Cu-W alloy. For the Cu-W alloy doped with 4 at.% Cr, at impact rates of 2800–3000 s⁻¹ and 3800-4000 s⁻¹, its dynamic compressive yield strengths reach 839 MPa and 828 MPa respectively. Compared to the Cu-W alloy without the addition of the Cr element, these values are 32.1 % and 33.8 % greater.</div></div>","PeriodicalId":385,"journal":{"name":"Materials Science and Engineering: A","volume":"940 ","pages":"Article 148582"},"PeriodicalIF":6.1,"publicationDate":"2025-05-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144167725","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":"Observation of interface disruption and Lomer-Cottrell locks in a crept L12-strengthened Ni-based superalloy","authors":"Muhammad Ishtiaq ,&nbsp;Joong Eun Jung ,&nbsp;Hyo Ju Bae ,&nbsp;Dae Won Yun ,&nbsp;Sung-Gyu Kang ,&nbsp;Alireza Zargaran ,&nbsp;Young-Kook Lee ,&nbsp;Yoon-Suk Choi ,&nbsp;Jae Bok Seol","doi":"10.1016/j.msea.2025.148570","DOIUrl":"10.1016/j.msea.2025.148570","url":null,"abstract":"<div><div>High-temperature, creep-resistant Ni-based superalloys used in turbine blades for aviation and power generation offer a potential route toward global energy savings. However, the fundamental mechanisms governing their long-term creep failure remain insufficiently understood. In this study, we propose a compositionally modified Ni-based polycrystalline Inconel 738LC alloy by reducing Co and increasing Al content. This modification enhances the yield strength from 844 to 924 MPa and significantly improves creep resistance at 750 °C under 600 MPa compared to the conventional Inconel 738LC series. We investigated the creep deformation mechanisms by analyzing microstructural evolution—particularly at the γ/γ′ interfaces—using transmission electron microscopy (TEM) and atom probe tomography (APT). The results reveal that creep deformation generates stress concentration at the corners of cuboidal γ′ precipitates, leading to interfacial disruption and the formation of abundant Lomer–Cottrell (LC) locks. These features contribute to both localized softening and overall hardening effects. Further TEM dark-field imaging under two-beam conditions demonstrates that during the later stages of creep, LC dislocations are also formed along solute-segregated planar faults within the γ′ precipitates. These dislocations result from the cross-slip of <span><math><mrow><mfrac><mi>a</mi><mn>6</mn></mfrac><mrow><mo>[</mo><mrow><mn>1</mn><mover><mn>1</mn><mo>‾</mo></mover><mn>2</mn></mrow><mo>]</mo></mrow><mo>,</mo><mfrac><mi>a</mi><mn>6</mn></mfrac><mrow><mo>[</mo><mrow><mn>1</mn><mover><mn>1</mn><mo>‾</mo></mover><mn>0</mn></mrow><mo>]</mo></mrow><mo>,</mo><mfrac><mi>a</mi><mn>6</mn></mfrac><mrow><mo>[</mo><mrow><mn>1</mn><mover><mn>12</mn><mo>‾</mo></mover></mrow><mo>]</mo></mrow></mrow></math></span> superpartial dislocations along the γ′ planar faults, from octahedral {111} planes to cubic {001} planes. Even though numerous twins and stacking faults (SFs) are additionally seen in the current alloy upon creep, the presence of LC-locking sessile dislocations—formed at both the γ′/γ interfaces and along solute-rich planar faults within the γ′ precipitates—emerged as a key feature contributing to the enhanced creep resistance. Their formation hinders dislocation motion and stabilizes the microstructure under prolonged thermal stress. Consequently, these γ′-LC dislocations and the associated interface-disrupted configurations collectively improve creep strength and extend rupture life. This study offers valuable insights into LC locks-mediated creep mechanisms, highlighting a promising pathway for the design of next-generation Ni-based superalloys.</div></div>","PeriodicalId":385,"journal":{"name":"Materials Science and Engineering: A","volume":"940 ","pages":"Article 148570"},"PeriodicalIF":6.1,"publicationDate":"2025-05-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144166874","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":"Wire-arc additive manufacturing of high-strength Al-Cu alloy via synergistic strengthening of Cd microalloying and TiC nanoparticle","authors":"Xinyi Cai ,&nbsp;Caiyou Zeng ,&nbsp;Qingfu Yang ,&nbsp;Zihao Jiang ,&nbsp;Biao Ma ,&nbsp;Hongwei Li ,&nbsp;Baoqiang Cong","doi":"10.1016/j.msea.2025.148572","DOIUrl":"10.1016/j.msea.2025.148572","url":null,"abstract":"<div><div>The growing demand for efficiency manufacturing of large-scale complex structures with high performance has driven increased interest in wire arc additive manufacturing (WAAM). Al-Cu alloys, known for their excellent specific strength, are widely used in lightweight applications. However, the fabrication of Al-Cu alloy structures via WAAM often results in heterogeneous microstructures and porosity defects, which impairs mechanical properties. In this study, nanoscale TiC particles and Cd microalloying are introduced into Al-Cu alloy using the dual-wires WAAM method. The effects of TiC particles and Cd microalloying on microstructural evolution and mechanical properties of WAAM Al-Cu alloy are systematically investigated. The obtained results demonstrate that multiphase synergistically strengthened Al-Cu alloy exhibits a microstructure with fine equiaxed grains and significant suppression of porosity defects. The optimized heat treatment promotes the formation of high-density nanoscale θ′-Al₂Cu precipitates. The TiC/AlCuCd alloy in the vertical and horizontal directions showed an increase in YS, UTS, EL by 22.26 %, 25.61 %, 90.57 % and 24.32 %, 21.61 %, 85.16 %, respectively, compared to the AlCu alloy. The synergistic enhancement of strength and plasticity is achieved.</div></div>","PeriodicalId":385,"journal":{"name":"Materials Science and Engineering: A","volume":"940 ","pages":"Article 148572"},"PeriodicalIF":6.1,"publicationDate":"2025-05-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144166873","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 an excellent synergy of strength and ductility in heat-treated laser powder bed fused niobium-based alloys via ZrO2-induced sub-grains","authors":"Meng Qin ,&nbsp;Xiaodan Li ,&nbsp;Yubo Jia ,&nbsp;Yiwei Yu ,&nbsp;Jingyan Shang ,&nbsp;Ran Duan ,&nbsp;Qingjun Zhou ,&nbsp;Peng Dong ,&nbsp;Yong Xie ,&nbsp;Kai Feng ,&nbsp;Zhuguo Li","doi":"10.1016/j.msea.2025.148575","DOIUrl":"10.1016/j.msea.2025.148575","url":null,"abstract":"<div><div>Additive manufacturing of niobium-based alloys demonstrates great potential for the rapid production of complex components in extreme aerospace applications. However, the ductility of niobium-based alloys fabricated by the laser powder bed fusion (LPBF) method is insufficient, which limits their industrial applications. In this study, the Nb521 (Nb-5W-2Mo-1Zr) alloy with a dense microstructure (99.96 %) was successfully fabricated using LPBF with pre-alloyed powders. The results show that the as-built specimens exhibit a typical body-centered cubic (BCC) crystalline structure, with homogeneous and crack-free microstructures. After heat treatment (HT), the ultimate tensile strength and elongation achieved an excellent synergy, being 564.8 ± 6 MPa and 23.62 ± 2.05 %, respectively. Notably, nanoscale monoclinic ZrO₂ particles precipitated in the HTed specimens, and their precipitation behavior was demonstrated using the Vienna Ab-initio Simulation Package (VASP) code, thermodynamic calculations and diffusion coefficients analysis. The improved ductility is attributed to the decrease in dislocation density, the precipitation of ZrO₂, and the formation of sub-grains induced by the ZrO₂ precipitates, which effectively mitigates stress concentration during tensile testing. The fracture mode changed from transgranular to ductile fracture, characterized by numerous dimples. This work investigates the mechanism by which high-vacuum HT enhances the ductility of LPBF Nb521 alloy and provides a viable pathway for the industrial production of niobium-based alloys with an excellent synergy of strength and ductility.</div></div>","PeriodicalId":385,"journal":{"name":"Materials Science and Engineering: A","volume":"940 ","pages":"Article 148575"},"PeriodicalIF":6.1,"publicationDate":"2025-05-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144166963","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":"Evolution of microstructures and microtextures during hot deformation of solid solution-strengthened superalloys","authors":"Zhiren Sun ,&nbsp;Sen Yang ,&nbsp;Zipeng Wang ,&nbsp;Shuhui Zhao ,&nbsp;Kaikun Wang ,&nbsp;Jianye Zhou ,&nbsp;Wenliang Zhang","doi":"10.1016/j.msea.2025.148566","DOIUrl":"10.1016/j.msea.2025.148566","url":null,"abstract":"<div><div>Using Electron Backscatter Diffraction (EBSD) and Transmission Electron Microscopy (TEM), the evolution of microstructures and microtextures of the ERNiCrMo-3 alloy under various deformation conditions were investigated and the slip characteristics of dominant grains with different orientations were analyzed. The results indicate that both the overall structures, as well as the recrystallized structures without significant grain growth, form a &lt;110&gt; fiber texture. Additionally, a higher proportion of the original structure corresponds to a higher maximum measured pole density (PMAX). In contrast, the recrystallized structures with pronounced grain growth tend to rotate to &lt;001&gt; axis due to preferential grain growth. The micro textures are primarily characterized by <span><math><mrow><mi>α</mi></mrow></math></span>-fiber textures composed of Brass, Goss, and P components under different deformation conditions. The Brass component is most prominent at the initial stage of dynamic recrystallization (DRX), while the Goss texture increases significantly under conditions favorable for DRX. As DRX progresses to completion, all texture components weakened. Grains with dominant orientations of Brass, Goss, or P have at least two slip systems activated, leading to the formation of dislocation wall substructures parallel to the slip planes within the grains. Orientation-dependent slip results in specific directions being softer or harder within the grains. Under the influence of slip, the ERNiCrMo-3 alloy readily forms a Brass texture. Due to differences in structural energy and Schmid factors between the Brass texture and other textures, the Brass component occupies a larger proportion under various conditions.</div></div>","PeriodicalId":385,"journal":{"name":"Materials Science and Engineering: A","volume":"940 ","pages":"Article 148566"},"PeriodicalIF":6.1,"publicationDate":"2025-05-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144154729","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":"Microstructural evolution mechanisms and cryogenic mechanical properties of induction-melted CoNiCr2 eutectic medium entropy alloy","authors":"Haibin Wu ,&nbsp;Weili Wang ,&nbsp;Tianwei Liu ,&nbsp;Pengxu Yan ,&nbsp;Wei Ren ,&nbsp;Jian Chen","doi":"10.1016/j.msea.2025.148578","DOIUrl":"10.1016/j.msea.2025.148578","url":null,"abstract":"<div><div>The tensile mechanical properties of eutectic multi-principal element alloys consisting of solid solution phases and intermetallic compounds are usually unsatisfactory due to their brittleness, let alone the mechanical properties at cryogenic temperatures. In this work, a novel CoNiCr₂ lamellar eutectic medium entropy alloy, mainly composed of FCC-(Co,Ni) and σ-Co₂Cr₃ phases, was prepared by vacuum induction melting. The σ phase originated from the eutectoid transformation of the BCC-(Cr) phase at the low cooling rate of 28 K/min. In contrast, no σ phase was observed in the arc-remelted alloy, since the rapid cooling rate over 1.67 × 10⁴ K/min restrained the eutectoid decomposition. The compressive and tensile mechanical properties at liquid nitrogen temperature (LNT) were systematically investigated. A remarkable compressive yield strength and ductility synergy of 924 MPa and 21.8 % was obtained at LNT compared to room temperature (RT) values of 313 MPa and 37.1 %. The (Co,Ni)-σ interfacial strengthening and enhanced lattice friction stress were responsible for the improved compressive yield strength, while the more brittle σ phase slightly reduced ductility. Moreover, the deformation mechanisms were dominated by Lomer-Cottrell locks at RT, along with stacking faults and nanoscale deformation twins at LNT. This work may provide new insights for designing eutectic high/medium entropy alloys with superior mechanical properties for cryogenic applications.</div></div>","PeriodicalId":385,"journal":{"name":"Materials Science and Engineering: A","volume":"940 ","pages":"Article 148578"},"PeriodicalIF":6.1,"publicationDate":"2025-05-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144167718","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":"Continuous annealing of medium-Mn steels: Sensitivity of mechanical performance to minor changes in time-temperature heat treatment parameters","authors":"Adam Skowronek ,&nbsp;Krzysztof Radwański ,&nbsp;Liwia Sozańska-Jędrasik ,&nbsp;Krzysztof Matus ,&nbsp;Adam Grajcar","doi":"10.1016/j.msea.2025.148568","DOIUrl":"10.1016/j.msea.2025.148568","url":null,"abstract":"<div><div>Studies on the intercritical annealing of medium-Mn steel sheets mostly focus on batch annealing conditions, a multi-hour process with low economic and technological efficiency. The literature on continuous annealing of these steels, which is crucial for their large-scale industrial production, is limited and primarily focuses on specific aspects of the process like annealing temperature or time. The following study comprehensively addresses all of the most important parameters of continuous annealing of Al-added medium-Mn steels. A broad range of soaking temperatures (700–760 °C) and times (2–120 s) was analyzed for heating (3 °C/s) and cooling (1 °C/s) conditions that are favorable for retaining austenite stability and feasible for industrial production. The effects of these conditions on the chemical and mechanical stability of retained austenite were examined. The resulting microstructures were correlated with the mechanical properties of the heat-treated steel. This allowed to determine the technological window for continuous annealing of medium-Mn steels. Moreover, the fractions and stability of retained austenite in a range from 18 to 34 %, for all applied thermal cycles, were linked to changes in the steel's mechanical properties. This confirmed that a high fraction of retained austenite alone is insufficient for achieving high plasticity. The key factor is the optimal mechanical stability of the austenite phase, as evidenced by the significantly better plasticity observed in a sample with 32 % RA compared to one containing 41 % RA. Furthermore, the relationship between global and local plasticity changes significantly as the stability of retained austenite decreases.</div></div>","PeriodicalId":385,"journal":{"name":"Materials Science and Engineering: A","volume":"940 ","pages":"Article 148568"},"PeriodicalIF":6.1,"publicationDate":"2025-05-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144137717","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":"Improving the mechanical performance of FeCoNi compositionally complex alloys through Al and V additions: Optimizing phase stability and microstructure","authors":"Dekun Si ,&nbsp;Zhenlu Cui ,&nbsp;Jilei Zhang ,&nbsp;Shunli Zhao ,&nbsp;Qingwei Gao ,&nbsp;Jiyao Zhang ,&nbsp;Xiaoming Liu ,&nbsp;Kaiwen Lu ,&nbsp;Pingping Liu ,&nbsp;Jianhong Gong ,&nbsp;Xiaoliang Han ,&nbsp;Weidong Song ,&nbsp;Jiri Orava ,&nbsp;Kaikai Song","doi":"10.1016/j.msea.2025.148565","DOIUrl":"10.1016/j.msea.2025.148565","url":null,"abstract":"<div><div>FCC-structured compositionally complex alloys (CCAs) are recognized for their excellent ductility at room temperature, but their relatively low strength limits their structural applications. This study addresses the strength-ductility trade-off by investigating the effects of Al and V contents on the phase stability, microstructure, and mechanical properties of (FeCoNi)₇₅V_{25−<em>x</em>}Al_<em>x</em> (<em>x</em> = 0–25 at.%) CCAs. The Al and V additions promote a phase transition from the ordered L1₂ to the disordered FCC phase upon heating, forming a multiscale hierarchical dual-phase structure that significantly enhances mechanical performance. Among them, the annealed (FeCoNi)₇₅V₁₆Al₉ alloy shows an impressive ultimate tensile strength of approximately 1504 MPa and a tensile elongation exceeding 15 %. Experimental observations indicate that the FCC phase is reinforced by L1₂ nanoprecipitates within grains and dot-like or needle-like L2₁ precipitates at grain boundaries. Additionally, the BCC islands are strengthened by L2₁ nanoprecipitates and toughened by dot-like or lath-like FCC/L1₂ phase. These combined strengthening mechanisms synergistically endow this CCA with its remarkably high yield strength. Moreover, the multiscale heterogeneous distribution of grains and phases, along with the diverse precipitate structures, enables the alloy to maintain high strain-hardening rates during plastic deformation, thus achieving an optimal balance of strength and ductility. These findings thus offer valuable insights for designing CCAs with improved mechanical properties.</div></div>","PeriodicalId":385,"journal":{"name":"Materials Science and Engineering: A","volume":"940 ","pages":"Article 148565"},"PeriodicalIF":6.1,"publicationDate":"2025-05-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144166876","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}