Pub Date : 2026-02-01Epub Date: 2025-11-20DOI: 10.1016/j.ijplas.2025.104556
Taeyeop Kim , Daegun You , Dongwoo Lee
The design of refractory complex-concentrated alloys (RCCAs) requires a comprehensive understanding of how alloying elements govern microstructure and mechanical response. Here, we report an integrated approach combining high-throughput experiments on Mo-Nb-Ti and Ta-Nb-Ti thin-film alloy libraries with molecular dynamics simulations to examine short range order (SRO). Composition dependent X-ray diffraction and electron microscopy investigations reveal that Mo-Nb-Ti alloys maintain fine grain sizes with minimal temperature dependence, whereas Ta-Nb-Ti alloys undergo substantial grain growth at elevated temperature. Nanoindentation mapping shows that Mo-Nb-Ti alloys consistently exhibit higher hardness and hardness-to-modulus ratios than Ta-Nb-Ti alloys, with strengthening largely affected by solid-solution effects. In contrast, the hardness reduction in Ta-Nb-Ti films deposited at high temperature is directly correlated with grain coarsening. Molecular dynamics simulations further demonstrate that SRO plays a critical role in strengthening and plasticity.
{"title":"Strengthening mechanisms of Mo–Nb–Ti and Ta–Nb–Ti complex-concentrated alloys: Data-driven insights from atomic descriptors and short-range order","authors":"Taeyeop Kim , Daegun You , Dongwoo Lee","doi":"10.1016/j.ijplas.2025.104556","DOIUrl":"10.1016/j.ijplas.2025.104556","url":null,"abstract":"<div><div>The design of refractory complex-concentrated alloys (RCCAs) requires a comprehensive understanding of how alloying elements govern microstructure and mechanical response. Here, we report an integrated approach combining high-throughput experiments on Mo-Nb-Ti and Ta-Nb-Ti thin-film alloy libraries with molecular dynamics simulations to examine short range order (SRO). Composition dependent X-ray diffraction and electron microscopy investigations reveal that Mo-Nb-Ti alloys maintain fine grain sizes with minimal temperature dependence, whereas Ta-Nb-Ti alloys undergo substantial grain growth at elevated temperature. Nanoindentation mapping shows that Mo-Nb-Ti alloys consistently exhibit higher hardness and hardness-to-modulus ratios than Ta-Nb-Ti alloys, with strengthening largely affected by solid-solution effects. In contrast, the hardness reduction in Ta-Nb-Ti films deposited at high temperature is directly correlated with grain coarsening. Molecular dynamics simulations further demonstrate that SRO plays a critical role in strengthening and plasticity.</div></div>","PeriodicalId":340,"journal":{"name":"International Journal of Plasticity","volume":"197 ","pages":"Article 104556"},"PeriodicalIF":12.8,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145553363","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-02-01Epub Date: 2026-01-07DOI: 10.1016/j.ijplas.2026.104607
Yanan Hu , Mingxue Feng , Chao Yu , Qianhua Kan , Xu Zhang , Shengchuan Wu , Leilei Wang , Feifan Wang , Yanling Xue , Guozheng Kang
This study systematically investigates the deformation behavior and internal damage evolution of wire + arc additively manufactured 2219 aluminum alloy across a temperature range of 133 K to 523 K using in-situ X-ray microtomography. Particular attention is devoted to clarifying the effects of both low and high temperatures on void nucleation, growth, and coalescence within the alloy. The results demonstrate that most voids nucleate through the fracture of eutectic θ (Al2Cu) phases. At elevated temperatures, reduced resistance to void nucleation and growth promotes extensive damage accumulation. In contrast, at cryogenic temperatures, increased resistance to nucleation leads to a lower void density; however, once voids nucleate and locally link, they rapidly coalesce into micro-cracks. Consequently, high-temperature failure is primarily governed by void growth, whereas cryogenic failure is dominated by void nucleation. Based on the identified critical microstructural attributes governing mechanical performance, a micromechanical constitutive model is constructed to describe the deformation behavior of the alloy. In the proposed model, the alloy is regarded as a heterogeneous composite consisting of an Al matrix, manufacturing defects, and eutectic θ phases. The temperature-dependent stress-strain responses are predicted using the Mori-Tanaka homogenization method, with the influence of temperature on damage evolution explicitly incorporated. The model successfully reproduces the stress-strain curves across the investigated temperature range and reflects the effect of damage evolution on the deformation behavior. Furthermore, Shapley additive explanations analysis identifies the temperature as the most influential factor affecting mechanical performance, surpassing the effects of both porosity and phase volume fraction.
{"title":"Unveiling deformation and damage evolution of WAAMed high-strength Al alloys across cryogenic to elevated temperatures","authors":"Yanan Hu , Mingxue Feng , Chao Yu , Qianhua Kan , Xu Zhang , Shengchuan Wu , Leilei Wang , Feifan Wang , Yanling Xue , Guozheng Kang","doi":"10.1016/j.ijplas.2026.104607","DOIUrl":"10.1016/j.ijplas.2026.104607","url":null,"abstract":"<div><div>This study systematically investigates the deformation behavior and internal damage evolution of wire + arc additively manufactured 2219 aluminum alloy across a temperature range of 133 K to 523 K using in-situ X-ray microtomography. Particular attention is devoted to clarifying the effects of both low and high temperatures on void nucleation, growth, and coalescence within the alloy. The results demonstrate that most voids nucleate through the fracture of eutectic θ (Al<sub>2</sub>Cu) phases. At elevated temperatures, reduced resistance to void nucleation and growth promotes extensive damage accumulation. In contrast, at cryogenic temperatures, increased resistance to nucleation leads to a lower void density; however, once voids nucleate and locally link, they rapidly coalesce into micro-cracks. Consequently, high-temperature failure is primarily governed by void growth, whereas cryogenic failure is dominated by void nucleation. Based on the identified critical microstructural attributes governing mechanical performance, a micromechanical constitutive model is constructed to describe the deformation behavior of the alloy. In the proposed model, the alloy is regarded as a heterogeneous composite consisting of an Al matrix, manufacturing defects, and eutectic θ phases. The temperature-dependent stress-strain responses are predicted using the Mori-Tanaka homogenization method, with the influence of temperature on damage evolution explicitly incorporated. The model successfully reproduces the stress-strain curves across the investigated temperature range and reflects the effect of damage evolution on the deformation behavior. Furthermore, Shapley additive explanations analysis identifies the temperature as the most influential factor affecting mechanical performance, surpassing the effects of both porosity and phase volume fraction.</div></div>","PeriodicalId":340,"journal":{"name":"International Journal of Plasticity","volume":"197 ","pages":"Article 104607"},"PeriodicalIF":12.8,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145920593","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-02-01Epub Date: 2026-01-01DOI: 10.1016/j.ijplas.2025.104606
Minwoo Park , Deunbom Chung , Wanchuck Woo , Seungcheol Oh , Kyeongjae Jeong , Heung Nam Han
This study proposes an integrated finite element (FE) simulation and convolutional neural network (CNN) model designed for the simultaneous prediction of plastic properties and surface in-plane non-equibiaxial residual stress from spherical indentation responses. By eliminating the need for stress-free reference specimens, the proposed framework enables non-destructive prediction. The framework leverages indentation load-depth curves and directional deformation profiles derived from validated FE simulations. Sensitivity analyses identify the indenter radius and penetration ratio as critical factors for improving prediction accuracy and maximizing the sensitivity of indentation responses to variations in residual stress. The influence of non-equibiaxial residual stress states on indentation behavior is further elucidated through a mechanistic investigation, which reveals a close association with cumulative volumetric changes in equivalent plastic strain near the indentation zone. The CNN training performance supports the sensitivity-based determination of optimal indentation settings. The model is shown to achieve a mean absolute error corresponding to below 5 % on average for residual stresses, while the plasticity parameters are also well captured. Experimental assessment on copper specimens with homogeneous residual stress fields verifies the accuracy and adaptability of the developed FE–CNN model. Further validation using additively manufactured stainless steel, exhibiting complex heterogeneous residual stresses, shows strong consistency with neutron diffraction measurements. This FE–CNN framework presents a robust and scalable approach for comprehensive mechanical characterization, offering substantial benefits for assessing structural integrity and reliability across diverse industrial applications without recourse to destructive testing.
{"title":"Indentation-informed convolutional neural network for simultaneous prediction of non-equibiaxial residual stress and plastic flow","authors":"Minwoo Park , Deunbom Chung , Wanchuck Woo , Seungcheol Oh , Kyeongjae Jeong , Heung Nam Han","doi":"10.1016/j.ijplas.2025.104606","DOIUrl":"10.1016/j.ijplas.2025.104606","url":null,"abstract":"<div><div>This study proposes an integrated finite element (FE) simulation and convolutional neural network (CNN) model designed for the simultaneous prediction of plastic properties and surface in-plane non-equibiaxial residual stress from spherical indentation responses. By eliminating the need for stress-free reference specimens, the proposed framework enables non-destructive prediction. The framework leverages indentation load-depth curves and directional deformation profiles derived from validated FE simulations. Sensitivity analyses identify the indenter radius and penetration ratio as critical factors for improving prediction accuracy and maximizing the sensitivity of indentation responses to variations in residual stress. The influence of non-equibiaxial residual stress states on indentation behavior is further elucidated through a mechanistic investigation, which reveals a close association with cumulative volumetric changes in equivalent plastic strain near the indentation zone. The CNN training performance supports the sensitivity-based determination of optimal indentation settings. The model is shown to achieve a mean absolute error corresponding to below 5 % on average for residual stresses, while the plasticity parameters are also well captured. Experimental assessment on copper specimens with homogeneous residual stress fields verifies the accuracy and adaptability of the developed FE–CNN model. Further validation using additively manufactured stainless steel, exhibiting complex heterogeneous residual stresses, shows strong consistency with neutron diffraction measurements. This FE–CNN framework presents a robust and scalable approach for comprehensive mechanical characterization, offering substantial benefits for assessing structural integrity and reliability across diverse industrial applications without recourse to destructive testing.</div></div>","PeriodicalId":340,"journal":{"name":"International Journal of Plasticity","volume":"197 ","pages":"Article 104606"},"PeriodicalIF":12.8,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145894280","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-02-01Epub Date: 2025-12-20DOI: 10.1016/j.ijplas.2025.104596
Yunjian Bai , Yaoyao Wang , Yanle Li , Yansen Li , Guo-jian Lyu , Heng Chen , Chenglong Yang , Fangyi Li
Additive manufacturing (AM) enables the tailored strength-ductility synergy of metastable high-entropy alloys (M-HEAs) by precisely regulating their metastable characteristics. However, the paucity of research on the cryogenic performance of AM-fabricated M-HEAs has impeded their reliable deployment in low-temperature engineering scenarios. This study systematically investigates the Co34Cr20Fe34Ni6Mn6 M-HEA, analyzing its mechanical behavior, microstructural evolution, and deformation mechanisms at cryogenic temperature (77 K), with comparative analysis against its room-temperature (298 K) properties. Additionally, the influence of manufacturing processes (cast vs. AM) on the microstructure and deformation was examined. The results reveal that the sufficient γ-phase retained by the AM process effectively overcomes the limitation of insufficient phase transformation capacity in cast sample. At 77 K, the AM-fabricated sample not only effectively mitigates the grain orientation dependence of phase transformation observed at 298 K—facilitating a uniform γ→ε transformation across the entire sample—but also undergoes a subsequent reverse ε→γ transformation. This reversible phase transformation behavior endows the alloy with an anomalous transformation-induced plasticity (TRIP) effect. The reverse ε→γ transformation is attributed to the combined effects of stacking fault energy/Gibbs free energy, local dissipative heating, and the local stress-strain field. Notably, the anomalous TRIP effect contributes to remarkable hardening, doubling the tensile strength while retaining excellent ductility. Furthermore, this study reveals a cooperative-to-competitive transition in deformation mechanisms between room and cryogenic temperatures. At 298 K, the TRIP effect operates synergistically with full dislocation slip, whereas at 77 K, the TRIP effect competes with full dislocation slip and gradually supplants it as the dominant mechanism. These findings yield cutting-edge insights into the deformation mechanisms of AM-fabricated M-HEAs under cryogenic conditions, offering critical reference for their targeted optimization and engineering application in low-temperature environments.
{"title":"Anomalous TRIP effect in an additively manufactured metastable high-entropy alloy at cryogenic temperatures: Implications for mechanical properties, microstructural evolution, and deformation mechanism","authors":"Yunjian Bai , Yaoyao Wang , Yanle Li , Yansen Li , Guo-jian Lyu , Heng Chen , Chenglong Yang , Fangyi Li","doi":"10.1016/j.ijplas.2025.104596","DOIUrl":"10.1016/j.ijplas.2025.104596","url":null,"abstract":"<div><div>Additive manufacturing (AM) enables the tailored strength-ductility synergy of metastable high-entropy alloys (M-HEAs) by precisely regulating their metastable characteristics. However, the paucity of research on the cryogenic performance of AM-fabricated M-HEAs has impeded their reliable deployment in low-temperature engineering scenarios. This study systematically investigates the Co<sub>34</sub>Cr<sub>20</sub>Fe<sub>34</sub>Ni<sub>6</sub>Mn<sub>6</sub> M-HEA, analyzing its mechanical behavior, microstructural evolution, and deformation mechanisms at cryogenic temperature (77 K), with comparative analysis against its room-temperature (298 K) properties. Additionally, the influence of manufacturing processes (cast vs. AM) on the microstructure and deformation was examined. The results reveal that the sufficient γ-phase retained by the AM process effectively overcomes the limitation of insufficient phase transformation capacity in cast sample. At 77 K, the AM-fabricated sample not only effectively mitigates the grain orientation dependence of phase transformation observed at 298 K—facilitating a uniform γ→ε transformation across the entire sample—but also undergoes a subsequent reverse ε→γ transformation. This reversible phase transformation behavior endows the alloy with an anomalous transformation-induced plasticity (TRIP) effect. The reverse ε→γ transformation is attributed to the combined effects of stacking fault energy/Gibbs free energy, local dissipative heating, and the local stress-strain field. Notably, the anomalous TRIP effect contributes to remarkable hardening, doubling the tensile strength while retaining excellent ductility. Furthermore, this study reveals a cooperative-to-competitive transition in deformation mechanisms between room and cryogenic temperatures. At 298 K, the TRIP effect operates synergistically with full dislocation slip, whereas at 77 K, the TRIP effect competes with full dislocation slip and gradually supplants it as the dominant mechanism. These findings yield cutting-edge insights into the deformation mechanisms of AM-fabricated M-HEAs under cryogenic conditions, offering critical reference for their targeted optimization and engineering application in low-temperature environments.</div></div>","PeriodicalId":340,"journal":{"name":"International Journal of Plasticity","volume":"197 ","pages":"Article 104596"},"PeriodicalIF":12.8,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145796131","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-02-01Epub Date: 2025-12-26DOI: 10.1016/j.ijplas.2025.104601
Yufeng Song , Lijie Wang , Yuqiang Chen , Wenhui Liu , Ziyi Teng , Qiang Hu , Mingwang Fu
Laminated aluminum alloys (LAAs) are recognized as pivotal materials in aerospace and automotive structures, due to their low density and high specific strength. However, there is an inverse relationship between the strength and plasticity of these alloys, which restricts their further applications in a low-carbon economy. This study proposes the design of micron-scale pure Al interlayers between AA2024/AA7075 layers to inversely strengthen the LAAs by achieving collaborative deformation through interlayer stress gradients and dislocation path modulation, enabling simultaneous enhancement of strength and plasticity. Notably, the micron-layered Al composite (MLAC) exhibits an ultimate tensile strength of 503.4 MPa and elongation of 13.3 %, which are 18.6 % and 29.1 % higher than those of the traditional layered composites (TLACs), significantly surpassing the limitation of the mechanical properties of laminated materials obeying the rule of mixtures (ROM). The underlying strengthening–ductilizing mechanisms are unveiled by in-situ electron backscatter diffraction (EBSD), digital image correlation (DIC), crystal plasticity (CP), and molecular dynamics (MD) based simulations. Results reveal that the strength mismatch between the pure Al layer and the Al alloy layers induces progressive accumulation of soft-layer stress gradient, forming an interfacial stress-affected zone (ISAZs). These zones trigger intricate dislocation-grain interactions and evolve into networked strain bands through the coordinated activation of slip systems. By redistributing local stress fields, these strain bands promote plastic flow as the dominant stress dissipation pathway, dynamically balance interfacial stress concentrations, and induce subcritical microcrack formation, thereby suppressing the tendency for catastrophic brittle fractures. Consequently, these findings establish heterostructure-enabled interlayer design as an effective pathway to achieve strength–ductility synergy in AA2024/AA7075 laminates. The unveiled strengthening–ductilizing mechanism offers a conceptual framework for developing LAAs that transcend conventional mechanical property limitations, obeying ROM.
{"title":"Enhancing the strength and plasticity of laminated aluminum alloy by introducing micron-scale pure aluminum interlayers","authors":"Yufeng Song , Lijie Wang , Yuqiang Chen , Wenhui Liu , Ziyi Teng , Qiang Hu , Mingwang Fu","doi":"10.1016/j.ijplas.2025.104601","DOIUrl":"10.1016/j.ijplas.2025.104601","url":null,"abstract":"<div><div>Laminated aluminum alloys (LAAs) are recognized as pivotal materials in aerospace and automotive structures, due to their low density and high specific strength. However, there is an inverse relationship between the strength and plasticity of these alloys, which restricts their further applications in a low-carbon economy. This study proposes the design of micron-scale pure Al interlayers between AA2024/AA7075 layers to inversely strengthen the LAAs by achieving collaborative deformation through interlayer stress gradients and dislocation path modulation, enabling simultaneous enhancement of strength and plasticity. Notably, the micron-layered Al composite (MLAC) exhibits an ultimate tensile strength of 503.4 MPa and elongation of 13.3 %, which are 18.6 % and 29.1 % higher than those of the traditional layered composites (TLACs), significantly surpassing the limitation of the mechanical properties of laminated materials obeying the rule of mixtures (ROM). The underlying strengthening–ductilizing mechanisms are unveiled by in-situ electron backscatter diffraction (EBSD), digital image correlation (DIC), crystal plasticity (CP), and molecular dynamics (MD) based simulations. Results reveal that the strength mismatch between the pure Al layer and the Al alloy layers induces progressive accumulation of soft-layer stress gradient, forming an interfacial stress-affected zone (ISAZs). These zones trigger intricate dislocation-grain interactions and evolve into networked strain bands through the coordinated activation of slip systems. By redistributing local stress fields, these strain bands promote plastic flow as the dominant stress dissipation pathway, dynamically balance interfacial stress concentrations, and induce subcritical microcrack formation, thereby suppressing the tendency for catastrophic brittle fractures. Consequently, these findings establish heterostructure-enabled interlayer design as an effective pathway to achieve strength–ductility synergy in AA2024/AA7075 laminates. The unveiled strengthening–ductilizing mechanism offers a conceptual framework for developing LAAs that transcend conventional mechanical property limitations, obeying ROM.</div></div>","PeriodicalId":340,"journal":{"name":"International Journal of Plasticity","volume":"197 ","pages":"Article 104601"},"PeriodicalIF":12.8,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145844912","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-02-01Epub Date: 2025-12-13DOI: 10.1016/j.ijplas.2025.104581
Gang Hee Gu , Sang Guk Jeong , Jae Heung Lee , Stefanus Harjo , Wu Gong , Auezhan Amanov , Jae Wung Bae , Hyeonseok Kwon , Hyoung Seop Kim
Stacking fault energy (SFE) is an intrinsic property that governs the deformation behavior of metallic materials, including dislocation slip, deformation twinning, and phase transformation. In this study, we present a mechanistic perspective demonstrating that the ‘apparent’ SFE and the associated deformation behavior can be tailored by modifying only the localized microstructure (∼100 μm from the surface) through the application of surface severe plastic deformation. This process generates a well-defined gradient microstructure in the near-surface region through grain refinement and an increase in dislocation density. The reduction in apparent SFE induced by localized gradient structure enhances the driving force for martensitic transformation compared to its homogeneous counterpart. This effect originates from the preferential martensite nucleation sites provided by the localized gradient region, as well as from dynamic stress partitioning facilitated by phase interfaces and gradient heterostructure, which synergistically accelerate the growth of martensitic phase. As a result, the deformation behavior was effectively modulated, leading to significantly enhanced mechanical properties. In particular, partial microstructural modification enabled strength enhancement while minimizing the loss of ductility, in clear contrast to conventional approaches based solely on grain refinement or dislocation density enhancement. This work therefore provides phenomenological insight into how localized microstructural engineering can regulate deformation mechanisms and mechanical performance, representing advancements beyond the conventional understanding of mechanical behavior of heterostructured materials.
{"title":"Surface severe plastic deformation-enabled deformation behavior control and mechanical property enhancement in metastable ferrous medium-entropy alloys","authors":"Gang Hee Gu , Sang Guk Jeong , Jae Heung Lee , Stefanus Harjo , Wu Gong , Auezhan Amanov , Jae Wung Bae , Hyeonseok Kwon , Hyoung Seop Kim","doi":"10.1016/j.ijplas.2025.104581","DOIUrl":"10.1016/j.ijplas.2025.104581","url":null,"abstract":"<div><div>Stacking fault energy (SFE) is an intrinsic property that governs the deformation behavior of metallic materials, including dislocation slip, deformation twinning, and phase transformation. In this study, we present a mechanistic perspective demonstrating that the ‘apparent’ SFE and the associated deformation behavior can be tailored by modifying only the localized microstructure (∼100 μm from the surface) through the application of surface severe plastic deformation. This process generates a well-defined gradient microstructure in the near-surface region through grain refinement and an increase in dislocation density. The reduction in apparent SFE induced by localized gradient structure enhances the driving force for martensitic transformation compared to its homogeneous counterpart. This effect originates from the preferential martensite nucleation sites provided by the localized gradient region, as well as from dynamic stress partitioning facilitated by phase interfaces and gradient heterostructure, which synergistically accelerate the growth of martensitic phase. As a result, the deformation behavior was effectively modulated, leading to significantly enhanced mechanical properties. In particular, partial microstructural modification enabled strength enhancement while minimizing the loss of ductility, in clear contrast to conventional approaches based solely on grain refinement or dislocation density enhancement. This work therefore provides phenomenological insight into how localized microstructural engineering can regulate deformation mechanisms and mechanical performance, representing advancements beyond the conventional understanding of mechanical behavior of heterostructured materials.</div></div>","PeriodicalId":340,"journal":{"name":"International Journal of Plasticity","volume":"197 ","pages":"Article 104581"},"PeriodicalIF":12.8,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145753083","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-02-01Epub Date: 2025-12-28DOI: 10.1016/j.ijplas.2025.104603
Yufei Chen , Tiwen Lu , Xiyu Chen , Xiaoqi Hu , Ning Yao , Xiaofeng Yang , Haitao Lu , Kaishang Li , Binhan Sun , Yunjie Bi , Xian-Cheng Zhang , Shan-Tung Tu
Additive manufacturing (AM) provides a novel avenue for the fabrication of metal matrix nanocomposites with a uniform distribution of reinforcements and excellent static mechanical properties, while few studies have been conducted on their fatigue behavior. In this study, TiCnp/(CoCrNi)94Al3Ti3 nanocomposites were fabricated using powder bed fusion (PBF), with another representative AM processes-directed energy deposition (DED) as a reference for comparison. In the case of similar low-density defects, though PBF-sample had finer microstructure and higher tensile strength than DED-sample, its fatigue endurance limit (350 MPa) was markedly lower than that of the DED sample (550 MPa). Further investigation revealed that the fatigue initiation sources for DED-samples were pores, while fatigue failure of PBF-samples were mainly initiated from manufactured microcracks. Though the average volume of pores in DED (1.9 × 105 μm3) was significantly larger than microcracks in PBF (1.6 × 104 μm3), the latter posed a more serious threat to fatigue performance. Microcracks were associated with Ti segregation at grain boundaries (GBs) and strong solidification shrinkage, both induced by higher solidification rate of PBF. Finally, two methods were applied to reduce the risk of GB cracking in nanocomposites by adjusting the alloy composition. As a result, segregation at GBs in PBF-fabricated nanocomposites was mitigated, reducing the microcrack density and significantly improving the fatigue resistance. The work reveals the origin of microcrack susceptivity in PBF and offers a microstructural strategy for designing high-strength and fatigue-resistant nanocomposites.
{"title":"Revealing and mitigating the microcrack-sensitive fatigue behavior of laser powder bed fusion fabricated medium-entropy nanocomposites","authors":"Yufei Chen , Tiwen Lu , Xiyu Chen , Xiaoqi Hu , Ning Yao , Xiaofeng Yang , Haitao Lu , Kaishang Li , Binhan Sun , Yunjie Bi , Xian-Cheng Zhang , Shan-Tung Tu","doi":"10.1016/j.ijplas.2025.104603","DOIUrl":"10.1016/j.ijplas.2025.104603","url":null,"abstract":"<div><div>Additive manufacturing (AM) provides a novel avenue for the fabrication of metal matrix nanocomposites with a uniform distribution of reinforcements and excellent static mechanical properties, while few studies have been conducted on their fatigue behavior. In this study, TiC<sub>np</sub>/(CoCrNi)<sub>94</sub>Al<sub>3</sub>Ti<sub>3</sub> nanocomposites were fabricated using powder bed fusion (PBF), with another representative AM processes-directed energy deposition (DED) as a reference for comparison. In the case of similar low-density defects, though PBF-sample had finer microstructure and higher tensile strength than DED-sample, its fatigue endurance limit (350 MPa) was markedly lower than that of the DED sample (550 MPa). Further investigation revealed that the fatigue initiation sources for DED-samples were pores, while fatigue failure of PBF-samples were mainly initiated from manufactured microcracks. Though the average volume of pores in DED (1.9 × 10<sup>5</sup> μm<sup>3</sup>) was significantly larger than microcracks in PBF (1.6 × 10<sup>4</sup> μm<sup>3</sup>), the latter posed a more serious threat to fatigue performance. Microcracks were associated with Ti segregation at grain boundaries (GBs) and strong solidification shrinkage, both induced by higher solidification rate of PBF. Finally, two methods were applied to reduce the risk of GB cracking in nanocomposites by adjusting the alloy composition. As a result, segregation at GBs in PBF-fabricated nanocomposites was mitigated, reducing the microcrack density and significantly improving the fatigue resistance. The work reveals the origin of microcrack susceptivity in PBF and offers a microstructural strategy for designing high-strength and fatigue-resistant nanocomposites.</div></div>","PeriodicalId":340,"journal":{"name":"International Journal of Plasticity","volume":"197 ","pages":"Article 104603"},"PeriodicalIF":12.8,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145844880","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Tailoring composition modulation can be a powerful tool to increase strength and ductility of two- and multicomponent alloys. Here we suggest a model that describes the tensile behavior of alloys with three-dimensional composition undulation. Within the model, the stacking fault energy variation, misfit stresses and dislocation pinning by the inhomogeneous solid solution are considered simultaneously. The model reveals that the composition undulation wavelength that provides peak ultimate strength is determined by a balance of three strengthening mechanisms: 1) dislocation pinning by obstacles, which is enhanced at a small undulation wavelength, 2) resistance to dislocation motion due to stacking fault energy variation, which is highest at a moderate undulation wavelength, and 3) dislocation interaction with misfit stresses, which is most pronounced at a high undulation wavelength. In considering the two latter mechanisms we uncovered a sharp transition from the moderate to the high optimum undulation wavelength at a critical value of the ratio of the misfit to the stacking fault energy variation. The two latter mechanisms increase strength at the expense of reduced ductility and do not affect the product of the ultimate strength and the uniform elongation. In contrast, dislocation pinning by obstacles can increase both strength and ductility due to enhanced strain hardening.
{"title":"Modeling strength and ductility of alloys with intragrain compositional inhomogeneities","authors":"A.M. Smirnov , A.G. Sheinerman , X.T. Li , Z.J. Zhang","doi":"10.1016/j.ijplas.2025.104602","DOIUrl":"10.1016/j.ijplas.2025.104602","url":null,"abstract":"<div><div>Tailoring composition modulation can be a powerful tool to increase strength and ductility of two- and multicomponent alloys. Here we suggest a model that describes the tensile behavior of alloys with three-dimensional composition undulation. Within the model, the stacking fault energy variation, misfit stresses and dislocation pinning by the inhomogeneous solid solution are considered simultaneously. The model reveals that the composition undulation wavelength that provides peak ultimate strength is determined by a balance of three strengthening mechanisms: 1) dislocation pinning by obstacles, which is enhanced at a small undulation wavelength, 2) resistance to dislocation motion due to stacking fault energy variation, which is highest at a moderate undulation wavelength, and 3) dislocation interaction with misfit stresses, which is most pronounced at a high undulation wavelength. In considering the two latter mechanisms we uncovered a sharp transition from the moderate to the high optimum undulation wavelength at a critical value of the ratio of the misfit to the stacking fault energy variation. The two latter mechanisms increase strength at the expense of reduced ductility and do not affect the product of the ultimate strength and the uniform elongation. In contrast, dislocation pinning by obstacles can increase both strength and ductility due to enhanced strain hardening.</div></div>","PeriodicalId":340,"journal":{"name":"International Journal of Plasticity","volume":"197 ","pages":"Article 104602"},"PeriodicalIF":12.8,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145922261","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-02-01Epub Date: 2025-12-24DOI: 10.1016/j.ijplas.2025.104598
Adrien R. Cassagne , Dimitris C. Lagoudas , Jean-Briac le Graverend
A crystal-plasticity approach with a mean-field framework using a self-consistent approach was developed for complex thermo-mechanical loading in high-temperature shape memory alloys (HTSMAs). More specifically, an implicit scale transition rule called -transition rule was employed. A grain-size-dependent martensitic transformation activation criterion was implemented to offer a smooth transformation hardening behavior as well as a saturating transformation strain magnitude function of the local von Mises stress. Two complex loadings were considered: out-of-phase (OP), consisting of a simultaneous increase of stress and decrease of temperature, and in-phase (IP), consisting of a simultaneous increase of stress and temperature. The material parameters were calibrated using isobaric experiments at different stress levels. This calibration was then used to model complex loading paths to evaluate the relevance of using isobaric parameters for the description of complex paths. Computational results are evaluated based on their capability to reproduce the transformation, actuation, and residual strains experimentally observed for the different loading paths considered. Results show a robustness to predict different loading paths using a set of isobaric calibrated parameters. In-phase paths are described on a purely qualitative basis due to the lack of quantitative experimental data. The model developed can capture the first cycle response shape explained by an initial loading in the self-accommodated martensitic state.
{"title":"A multi-scale modeling of complex thermomechanical loading paths in high-temperature shape memory alloys using a crystal-plasticity framework","authors":"Adrien R. Cassagne , Dimitris C. Lagoudas , Jean-Briac le Graverend","doi":"10.1016/j.ijplas.2025.104598","DOIUrl":"10.1016/j.ijplas.2025.104598","url":null,"abstract":"<div><div>A crystal-plasticity approach with a mean-field framework using a self-consistent approach was developed for complex thermo-mechanical loading in high-temperature shape memory alloys (HTSMAs). More specifically, an implicit scale transition rule called <span><math><mi>β</mi></math></span>-transition rule was employed. A grain-size-dependent martensitic transformation activation criterion was implemented to offer a smooth transformation hardening behavior as well as a saturating transformation strain magnitude function of the local von Mises stress. Two complex loadings were considered: out-of-phase (OP), consisting of a simultaneous increase of stress and decrease of temperature, and in-phase (IP), consisting of a simultaneous increase of stress and temperature. The material parameters were calibrated using isobaric experiments at different stress levels. This calibration was then used to model complex loading paths to evaluate the relevance of using isobaric parameters for the description of complex paths. Computational results are evaluated based on their capability to reproduce the transformation, actuation, and residual strains experimentally observed for the different loading paths considered. Results show a robustness to predict different loading paths using a set of isobaric calibrated parameters. In-phase paths are described on a purely qualitative basis due to the lack of quantitative experimental data. The model developed can capture the first cycle response shape explained by an initial loading in the self-accommodated martensitic state.</div></div>","PeriodicalId":340,"journal":{"name":"International Journal of Plasticity","volume":"197 ","pages":"Article 104598"},"PeriodicalIF":12.8,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145822856","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-02-01Epub Date: 2025-12-15DOI: 10.1016/j.ijplas.2025.104582
Alireza Ostadrahimi , Amir Teimouri , Kshitiz Upadhyay , Guoqiang Li
This work introduces a constitutive modeling framework based on a physics-informed Temporal Convolutional Network (TCN) for capturing the extremely nonlinear thermoviscoelastic behavior of soft materials, including large cyclic elongations up to 200%, temperature-dependent viscoelasticity, and Mullins-type damage. In contrast to conventional Mullins or thermo-viscoelastic models—which require specifying hard-coded functional forms and calibrating numerous parameters across 8–12 experiments—the proposed framework defines a new evolution law for stress, damage, and reduced-time temperature effects through a causal temporal architecture. Time–temperature superposition is embedded directly via the Williams–Landel–Ferry (WLF) shift factor, making temperature an intrinsic driver for reduced time rather than an externally appended parameter. This allows the model to learn temperature–rate–damage coupling sequentially, without predefined analytical evolution equations. As a result, the framework requires only three experimental tests for training yet generalizes to six entirely unseen tests that span different temperatures, strain rates, cycle counts, and elongation levels. The model successfully extrapolates to regimes far outside the training domain, including temperatures not used in training, strain rates 2.5 × higher, elongations 50% greater, and significantly longer cyclic histories. Thermodynamic admissibility is promoted by softly enforcing the Clausius–Duhem inequality in the loss function, while damage evolution is constrained by physical principles. The resulting surrogate constitutes a new constitutive model expressed through physics-embedded sequence learning rather than traditional closed-form equations. The trained model is directly implementable in finite element solvers through a VUMAT subroutine, enabling predictive simulations under complex geometries and loading conditions. Its robustness to experimental uncertainty is demonstrated through accurate predictions under 20% Gaussian stress noise. Validation includes three training cases, six independent experimental tests, and a geometry-dependent deployment example involving cyclic Mullins damage in an open-hole specimen, all showing close agreement. These results demonstrate that embedding reduced-time physics into a TCN framework not only accelerates training and improves predictive accuracy but also establishes a fundamentally new, thermodynamically anchored constitutive formulation that surpasses the capabilities of traditional phenomenological models and existing ML-based surrogates.
{"title":"Stress softening damage in strongly nonlinear viscoelastic soft materials: A physics-informed data-driven constitutive model with time–temperature coupling","authors":"Alireza Ostadrahimi , Amir Teimouri , Kshitiz Upadhyay , Guoqiang Li","doi":"10.1016/j.ijplas.2025.104582","DOIUrl":"10.1016/j.ijplas.2025.104582","url":null,"abstract":"<div><div>This work introduces a constitutive modeling framework based on a physics-informed Temporal Convolutional Network (TCN) for capturing the extremely nonlinear thermoviscoelastic behavior of soft materials, including large cyclic elongations up to 200%, temperature-dependent viscoelasticity, and Mullins-type damage. In contrast to conventional Mullins or thermo-viscoelastic models—which require specifying hard-coded functional forms and calibrating numerous parameters across 8–12 experiments—the proposed framework defines a new evolution law for stress, damage, and reduced-time temperature effects through a causal temporal architecture. Time–temperature superposition is embedded directly via the Williams–Landel–Ferry (WLF) shift factor, making temperature an intrinsic driver for reduced time rather than an externally appended parameter. This allows the model to learn temperature–rate–damage coupling sequentially, without predefined analytical evolution equations. As a result, the framework requires only three experimental tests for training yet generalizes to six entirely unseen tests that span different temperatures, strain rates, cycle counts, and elongation levels. The model successfully extrapolates to regimes far outside the training domain, including temperatures not used in training, strain rates 2.5 × higher, elongations 50% greater, and significantly longer cyclic histories. Thermodynamic admissibility is promoted by softly enforcing the Clausius–Duhem inequality in the loss function, while damage evolution is constrained by physical principles. The resulting surrogate constitutes a new constitutive model expressed through physics-embedded sequence learning rather than traditional closed-form equations. The trained model is directly implementable in finite element solvers through a VUMAT subroutine, enabling predictive simulations under complex geometries and loading conditions. Its robustness to experimental uncertainty is demonstrated through accurate predictions under 20% Gaussian stress noise. Validation includes three training cases, six independent experimental tests, and a geometry-dependent deployment example involving cyclic Mullins damage in an open-hole specimen, all showing close agreement. These results demonstrate that embedding reduced-time physics into a TCN framework not only accelerates training and improves predictive accuracy but also establishes a fundamentally new, thermodynamically anchored constitutive formulation that surpasses the capabilities of traditional phenomenological models and existing ML-based surrogates.</div></div>","PeriodicalId":340,"journal":{"name":"International Journal of Plasticity","volume":"197 ","pages":"Article 104582"},"PeriodicalIF":12.8,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145838508","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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