Pub Date : 2025-12-01Epub Date: 2025-10-22DOI: 10.1016/j.ijplas.2025.104513
Vikram Roy , I.A. Khan , Anirban Patra
A crystal plasticity constitutive modeling framework is presented to model the inelastic deformation behavior of unirradiated and irradiated ferritic-martensitic steels. The model considers dislocation densities that evolve during inelastic deformation, as well as irradiation-induced defect densities and their sizes, as internal state variables. The model accounts for key deformation mechanisms - dislocation glide and climb - as well as the microstructural effects governing hardening, thermal creep, irradiation hardening, and irradiation creep. The model accounts for the effects of temperature, strain rate, and irradiation dose on hardening, and successfully reproduces the stress and temperature dependence of both thermal and irradiation creep. Validation against multiple experimental datasets confirms that the model predictions fall within the range of experimentally observed variability, particularly in predicting the irradiation-induced hardening and the steady-state creep rates across a wide range of thermal and irradiation conditions. Overall, this work establishes a robust, mechanistic framework for predicting the elevated temperature, irradiation-induced deformation behavior of ferritic-martensitic steels.
{"title":"Crystal plasticity modeling of hardening and creep in ferritic-martensitic alloys under thermal and irradiation environments","authors":"Vikram Roy , I.A. Khan , Anirban Patra","doi":"10.1016/j.ijplas.2025.104513","DOIUrl":"10.1016/j.ijplas.2025.104513","url":null,"abstract":"<div><div>A crystal plasticity constitutive modeling framework is presented to model the inelastic deformation behavior of unirradiated and irradiated ferritic-martensitic steels. The model considers dislocation densities that evolve during inelastic deformation, as well as irradiation-induced defect densities and their sizes, as internal state variables. The model accounts for key deformation mechanisms - dislocation glide and climb - as well as the microstructural effects governing hardening, thermal creep, irradiation hardening, and irradiation creep. The model accounts for the effects of temperature, strain rate, and irradiation dose on hardening, and successfully reproduces the stress and temperature dependence of both thermal and irradiation creep. Validation against multiple experimental datasets confirms that the model predictions fall within the range of experimentally observed variability, particularly in predicting the irradiation-induced hardening and the steady-state creep rates across a wide range of thermal and irradiation conditions. Overall, this work establishes a robust, mechanistic framework for predicting the elevated temperature, irradiation-induced deformation behavior of ferritic-martensitic steels.</div></div>","PeriodicalId":340,"journal":{"name":"International Journal of Plasticity","volume":"195 ","pages":"Article 104513"},"PeriodicalIF":12.8,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145463289","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 : 2025-12-01Epub Date: 2025-10-09DOI: 10.1016/j.ijplas.2025.104498
Jiawei Sun, Yuchuan Huang, Yangyang Xu, Jiaxin Yu, Zhihong Ye, Youjie Guo, Fangzhou Qi, Gaoming Zhu, Jie Wang, Guohua Wu, Hezhou Liu, Wencai Liu
The inherently low Young’s modulus and limited strength of Mg-Li alloys have long restricted their structural application potential. In this study, we developed a modulus-oriented TiB2/LAZ532 composite via rotary swaging, integrating particle reinforcement, severe plastic deformation, and interface engineering. Rotary swaging refined the grain structure to the submicron scale and introduced a high density of dislocation substructures, thereby enabling substantial strength improvement. Meanwhile, Li(Al, Zn) precipitates were observed to form at TiB2/matrix interfaces, as confirmed by TEM, phase-field simulations, FEA, and in-situ synchrotron XRD. These interfacial precipitates acted as middle layer reducing stress concentration and enhancing strain transfer across particle/matrix boundaries, thus achieving improved deformation compatibility. Owing to the dual contribution of matrix grain refinement/dislocation hardening and interfacial strain accommodation, the composite achieved an ultimate tensile strength of 455 MPa, Young’s modulus of 61 GPa, and a low density of 1.75 g/cm3. This unique combination of ultra-light weight and mechanical robustness highlights a functionally partitioned strengthening strategy, wherein reinforcement, processing, and interface design contribute complementary roles. The approach provides a generalizable pathway for designing next-generation lightweight Mg-Li structural materials.
{"title":"Achieving superior strength in high modulus Mg-Li matrix composites via rotary swaging with interfacial precipitation-induced strain compatibility","authors":"Jiawei Sun, Yuchuan Huang, Yangyang Xu, Jiaxin Yu, Zhihong Ye, Youjie Guo, Fangzhou Qi, Gaoming Zhu, Jie Wang, Guohua Wu, Hezhou Liu, Wencai Liu","doi":"10.1016/j.ijplas.2025.104498","DOIUrl":"10.1016/j.ijplas.2025.104498","url":null,"abstract":"<div><div>The inherently low Young’s modulus and limited strength of Mg-Li alloys have long restricted their structural application potential. In this study, we developed a modulus-oriented TiB<sub>2</sub>/LAZ532 composite via rotary swaging, integrating particle reinforcement, severe plastic deformation, and interface engineering. Rotary swaging refined the grain structure to the submicron scale and introduced a high density of dislocation substructures, thereby enabling substantial strength improvement. Meanwhile, Li(Al, Zn) precipitates were observed to form at TiB<sub>2</sub>/matrix interfaces, as confirmed by TEM, phase-field simulations, FEA, and in-situ synchrotron XRD. These interfacial precipitates acted as middle layer reducing stress concentration and enhancing strain transfer across particle/matrix boundaries, thus achieving improved deformation compatibility. Owing to the dual contribution of matrix grain refinement/dislocation hardening and interfacial strain accommodation, the composite achieved an ultimate tensile strength of 455 MPa, Young’s modulus of 61 GPa, and a low density of 1.75 g/cm<sup>3</sup>. This unique combination of ultra-light weight and mechanical robustness highlights a functionally partitioned strengthening strategy, wherein reinforcement, processing, and interface design contribute complementary roles. The approach provides a generalizable pathway for designing next-generation lightweight Mg-Li structural materials.</div></div>","PeriodicalId":340,"journal":{"name":"International Journal of Plasticity","volume":"195 ","pages":"Article 104498"},"PeriodicalIF":12.8,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145255207","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 : 2025-12-01Epub Date: 2025-10-30DOI: 10.1016/j.ijplas.2025.104510
Mingyu Lei , Jie Huang , Yifei Xing , Yiyuan Qian , Xiaohua Li , Xiaojun Wang , Xu Li , Bin Wen
Accurate prediction of creep behavior is crucial for ensuring the reliability and safety of structural materials in high-temperature applications. Existing creep models, however, often require extensive experimental calibration and are constrained by idealized assumptions or incomplete representation of fundamental physical mechanisms. Consequently, a critical knowledge gap remains in understanding the coupled effects of different creep mechanisms, which reduces the predictive capability under complex material and loading conditions. In this work, we propose a multi-mechanism coupled creep constitutive model with computable parameters to quantitatively link microstructural characteristics to macroscopic creep response without relying on experimental data fitting. Within a unified thermodynamic framework, the model explicitly incorporates the contributions of vacancy diffusion, dislocation slip, and climb, grain boundary (GB) sliding, deformation twinning, and void evolution. Comprehensive analyses are conducted to investigate the coupling effects among various creep mechanisms. Applications to representative metals and alloys demonstrate that the model accurately captures the entire creep process under diverse microstructural conditions, thereby validating its predictive accuracy and robustness. This work not only enhances the mechanistic understanding of creep but also provides a powerful computational tool for designing advanced materials under extreme loading conditions.
{"title":"A multi-mechanism coupled creep constitutive modeling with computable parameters","authors":"Mingyu Lei , Jie Huang , Yifei Xing , Yiyuan Qian , Xiaohua Li , Xiaojun Wang , Xu Li , Bin Wen","doi":"10.1016/j.ijplas.2025.104510","DOIUrl":"10.1016/j.ijplas.2025.104510","url":null,"abstract":"<div><div>Accurate prediction of creep behavior is crucial for ensuring the reliability and safety of structural materials in high-temperature applications. Existing creep models, however, often require extensive experimental calibration and are constrained by idealized assumptions or incomplete representation of fundamental physical mechanisms. Consequently, a critical knowledge gap remains in understanding the coupled effects of different creep mechanisms, which reduces the predictive capability under complex material and loading conditions. In this work, we propose a multi-mechanism coupled creep constitutive model with computable parameters to quantitatively link microstructural characteristics to macroscopic creep response without relying on experimental data fitting. Within a unified thermodynamic framework, the model explicitly incorporates the contributions of vacancy diffusion, dislocation slip, and climb, grain boundary (GB) sliding, deformation twinning, and void evolution. Comprehensive analyses are conducted to investigate the coupling effects among various creep mechanisms. Applications to representative metals and alloys demonstrate that the model accurately captures the entire creep process under diverse microstructural conditions, thereby validating its predictive accuracy and robustness. This work not only enhances the mechanistic understanding of creep but also provides a powerful computational tool for designing advanced materials under extreme loading conditions.</div></div>","PeriodicalId":340,"journal":{"name":"International Journal of Plasticity","volume":"195 ","pages":"Article 104510"},"PeriodicalIF":12.8,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145404349","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 : 2025-12-01Epub Date: 2025-11-01DOI: 10.1016/j.ijplas.2025.104537
Yue Wu , Shuai Xu , Renhao Wu , Tao Wang , Hyoung Seop Kim , Haiming Zhang
Conventional crystal plasticity (CP) models, which assume intragranular homogeneity, struggle to capture the complex deformation behavior of additively manufactured (AM) materials that exhibit pronounced initial microstructural heterogeneity. In this study, we develop a novel CP modeling approach that explicitly incorporates initial orientation gradients and dislocation density variations, enabling accurate representation of intragranular heterogeneities. By integrating full-field simulations with in situ tensile testing and high-resolution EBSD, we comparably investigate the mechanical responses and deformation mechanisms of both AM and conventionally manufactured (CM) 316 L stainless steels. The proposed model shows superior agreement with experimental measurements, accurately capturing stress and strain hotpots, dislocation evolution, and the emergence of intragranular shear band networks. These networks, strongly affected by initial microstructure heterogeneity, exhibit complex propagation and interaction behaviors, fundamentally altering strain partitioning path and resulting in persistent differences from predictions of conventional models. While overall stress levels remain comparable between models, the conventional approach significantly underestimates strain heterogeneity and overestimates stress heterogeneity, particularly in AM materials. Notably, the CM samples exhibit strain accumulation at grain boundaries and triple junctions, whereas the AM samples redistribute strain into grain interiors, facilitated by inherited heterogeneity. This enhances intergranular deformation compatibility, suppresses stress triaxiality in critical regions and activates more slip systems, ultimately improving ductility without compromising strength. This work highlights the limitations of traditional CP modeling and establishes the critical importance of incorporating microstructural gradients for accurately predicting mechanical behavior in heterogeneous materials. Beyond validation, the model provides a robust tool for microstructure-informed design, offering new insights for optimizing the strength-ductility synergy in architectured materials such as AM alloys.
{"title":"Microstructure-informed crystal plasticity modeling incorporating initial intragranular heterogeneities: insights into deformation mechanisms of additively manufactured alloy","authors":"Yue Wu , Shuai Xu , Renhao Wu , Tao Wang , Hyoung Seop Kim , Haiming Zhang","doi":"10.1016/j.ijplas.2025.104537","DOIUrl":"10.1016/j.ijplas.2025.104537","url":null,"abstract":"<div><div>Conventional crystal plasticity (CP) models, which assume intragranular homogeneity, struggle to capture the complex deformation behavior of additively manufactured (AM) materials that exhibit pronounced initial microstructural heterogeneity. In this study, we develop a novel CP modeling approach that explicitly incorporates initial orientation gradients and dislocation density variations, enabling accurate representation of intragranular heterogeneities. By integrating full-field simulations with in situ tensile testing and high-resolution EBSD, we comparably investigate the mechanical responses and deformation mechanisms of both AM and conventionally manufactured (CM) 316 L stainless steels. The proposed model shows superior agreement with experimental measurements, accurately capturing stress and strain hotpots, dislocation evolution, and the emergence of intragranular shear band networks. These networks, strongly affected by initial microstructure heterogeneity, exhibit complex propagation and interaction behaviors, fundamentally altering strain partitioning path and resulting in persistent differences from predictions of conventional models. While overall stress levels remain comparable between models, the conventional approach significantly underestimates strain heterogeneity and overestimates stress heterogeneity, particularly in AM materials. Notably, the CM samples exhibit strain accumulation at grain boundaries and triple junctions, whereas the AM samples redistribute strain into grain interiors, facilitated by inherited heterogeneity. This enhances intergranular deformation compatibility, suppresses stress triaxiality in critical regions and activates more slip systems, ultimately improving ductility without compromising strength. This work highlights the limitations of traditional CP modeling and establishes the critical importance of incorporating microstructural gradients for accurately predicting mechanical behavior in heterogeneous materials. Beyond validation, the model provides a robust tool for microstructure-informed design, offering new insights for optimizing the strength-ductility synergy in architectured materials such as AM alloys.</div></div>","PeriodicalId":340,"journal":{"name":"International Journal of Plasticity","volume":"195 ","pages":"Article 104537"},"PeriodicalIF":12.8,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145411931","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 : 2025-12-01Epub Date: 2025-11-05DOI: 10.1016/j.ijplas.2025.104545
Fusheng Tan , Xin Liu , Xuefeng Liang , Yinan Cui
Vacancy properties in High-entropy alloys (HEAs) play a critical role in governing high-temperature microstructural stability, yet the fundamental relationship between Vacancy Formation Energy (VFE) and heterogeneous Local Atomic Environments (LAE) in HEAs remains far from well understood, owing to the complex and heterogeneous nature of LAE. To address this, we developed an interpretable machine learning framework integrating high-throughput molecular dynamics simulations and physics-informed features. Using CoNiCrFeMn as model system, our approach achieves exceptional prediction accuracy (R² = 0.98) for VFE. It is found that the LAE within the first-nearest-neighbor shell around vacancy dominates VFE variations, and the local atomic spatial ordering exerts influence on VFE comparable in magnitude to local chemical composition. Based on the designated LAE descriptor, namely multilevel element pair probability, and feature analysis-guided physics interpretation, we identify for the first time the physical origin of LAE-mediated VFE as the synergistic strong/weak-bond elements competition and lattice distortion effects. Specifically, coexisting strong-bond (e.g., Ni) and weak-bond (e.g., Mn) atoms in 1NN shell around central vacancy drive offsetting displacements through lattice distortion, dynamically tailoring VFE. The mechanism explains anomalously high lattice distortion and elevated vacancy concentrations observed in Mn-containing CoNiCrFeMn HEAs, and further enables a strategy for enhancing vacancy stability via annealing-induced elemental aggregation. These results establish a theoretical framework for defect engineering in the design of complex solid-solution alloys.
{"title":"Data-inspired atomic environment-dependence of vacancy formation energy in high-entropy alloys","authors":"Fusheng Tan , Xin Liu , Xuefeng Liang , Yinan Cui","doi":"10.1016/j.ijplas.2025.104545","DOIUrl":"10.1016/j.ijplas.2025.104545","url":null,"abstract":"<div><div>Vacancy properties in High-entropy alloys (HEAs) play a critical role in governing high-temperature microstructural stability, yet the fundamental relationship between Vacancy Formation Energy (VFE) and heterogeneous Local Atomic Environments (LAE) in HEAs remains far from well understood, owing to the complex and heterogeneous nature of LAE. To address this, we developed an interpretable machine learning framework integrating high-throughput molecular dynamics simulations and physics-informed features. Using CoNiCrFeMn as model system, our approach achieves exceptional prediction accuracy (R² = 0.98) for VFE. It is found that the LAE within the first-nearest-neighbor shell around vacancy dominates VFE variations, and the local atomic spatial ordering exerts influence on VFE comparable in magnitude to local chemical composition. Based on the designated LAE descriptor, namely multilevel element pair probability, and feature analysis-guided physics interpretation, we identify for the first time the physical origin of LAE-mediated VFE as the synergistic strong/weak-bond elements competition and lattice distortion effects. Specifically, coexisting strong-bond (e.g., Ni) and weak-bond (e.g., Mn) atoms in 1NN shell around central vacancy drive offsetting displacements through lattice distortion, dynamically tailoring VFE. The mechanism explains anomalously high lattice distortion and elevated vacancy concentrations observed in Mn-containing CoNiCrFeMn HEAs, and further enables a strategy for enhancing vacancy stability via annealing-induced elemental aggregation. These results establish a theoretical framework for defect engineering in the design of complex solid-solution alloys.</div></div>","PeriodicalId":340,"journal":{"name":"International Journal of Plasticity","volume":"195 ","pages":"Article 104545"},"PeriodicalIF":12.8,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145447595","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 : 2025-12-01Epub Date: 2025-10-22DOI: 10.1016/j.ijplas.2025.104523
Xiang Xu , Peilin Fu , Yusong Fan , Chao Yu , Jianping Zhao , Guhui Gao , Ping Wang , Zefeng Wen , Guozheng Kang , Qianhua Kan
The fatigue damage evolution of carbide-free bainitic (CFB) rail steels is highly complicated due to their unique deformation mechanisms and ratcheting-fatigue interaction. To account for the effects of martensitic transformation and damage on the whole-life ratcheting of CFB rail steels, an anisotropic damage-coupled cyclic plastic model is developed. The isotropic resistance and back stress associated with the transformation hardening induced by plastic deformation are incorporated into the transformation driving force, enabling a more reasonable description of martensitic transformation in cyclic softening materials. Moreover, the martensitic volume fraction and maximum equivalent plastic strain are coupled into the damage evolution equation to reflect the adverse effect of martensitic transformation on the fatigue life and damage acceleration caused by the ratcheting. The proposed model reasonably captures the evolution of the damage variable and martensitic volume fraction during cyclic loading, and accurately predicts the fatigue life of the material under various uniaxial and multiaxial cyclic loading conditions, providing a theoretical foundation for evaluating the long-term service behavior of CFB rails during rolling contact.
{"title":"An anisotropic damage-coupled cyclic plastic model for whole-life ratcheting of carbide-free bainitic rail steels considering the martensitic transformation","authors":"Xiang Xu , Peilin Fu , Yusong Fan , Chao Yu , Jianping Zhao , Guhui Gao , Ping Wang , Zefeng Wen , Guozheng Kang , Qianhua Kan","doi":"10.1016/j.ijplas.2025.104523","DOIUrl":"10.1016/j.ijplas.2025.104523","url":null,"abstract":"<div><div>The fatigue damage evolution of carbide-free bainitic (CFB) rail steels is highly complicated due to their unique deformation mechanisms and ratcheting-fatigue interaction. To account for the effects of martensitic transformation and damage on the whole-life ratcheting of CFB rail steels, an anisotropic damage-coupled cyclic plastic model is developed. The isotropic resistance and back stress associated with the transformation hardening induced by plastic deformation are incorporated into the transformation driving force, enabling a more reasonable description of martensitic transformation in cyclic softening materials. Moreover, the martensitic volume fraction and maximum equivalent plastic strain are coupled into the damage evolution equation to reflect the adverse effect of martensitic transformation on the fatigue life and damage acceleration caused by the ratcheting. The proposed model reasonably captures the evolution of the damage variable and martensitic volume fraction during cyclic loading, and accurately predicts the fatigue life of the material under various uniaxial and multiaxial cyclic loading conditions, providing a theoretical foundation for evaluating the long-term service behavior of CFB rails during rolling contact.</div></div>","PeriodicalId":340,"journal":{"name":"International Journal of Plasticity","volume":"195 ","pages":"Article 104523"},"PeriodicalIF":12.8,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145382369","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 : 2025-12-01Epub Date: 2025-10-26DOI: 10.1016/j.ijplas.2025.104532
Wei Zhang , Gang Ma , Jiangzhou Mei , Rui Wang , Daren Zhang , Wanda Cao , Wei Zhou
The spatiotemporal evolution of local plastic zones, where particles undergo irreversible and cooperative rearrangements, governs the shear band formation and macroscopic yielding of granular materials. Although prior studies have shown that these zones undergo a percolation-like transition from localized to system-spanning scales under external shear, the underlying mechanisms driving this evolution remain poorly understood. In this study, we conduct in situ X-ray computed tomography (CT) triaxial shear tests on Ottawa sand, enabling high-resolution reconstruction of particle-scale kinematics. We identify active clusters characterized by intense nonaffine motion and systematically track their spatiotemporal evolution throughout the entire shearing process. By integrating structural and dynamic attributes of these clusters, we introduce a metric termed adaptability to quantify their resilience and persistence under shear. We demonstrate that, analogous to natural selection in ecological systems, clusters with higher adaptability are more likely to survive, proliferate, and merge with neighboring clusters. This self-reinforcing process enhances the overall adaptability of the granular system and governs the development of shear localization in dense assemblies. Our work provides the first experimental characterization of dynamic heterogeneity in irregular granular materials and offers a novel perspective on the underlying mechanisms governing shear localization, with broad implications for the study of granular materials.
{"title":"Dynamic heterogeneity of irregular granular materials captured by in situ X-ray imaging","authors":"Wei Zhang , Gang Ma , Jiangzhou Mei , Rui Wang , Daren Zhang , Wanda Cao , Wei Zhou","doi":"10.1016/j.ijplas.2025.104532","DOIUrl":"10.1016/j.ijplas.2025.104532","url":null,"abstract":"<div><div>The spatiotemporal evolution of local plastic zones, where particles undergo irreversible and cooperative rearrangements, governs the shear band formation and macroscopic yielding of granular materials. Although prior studies have shown that these zones undergo a percolation-like transition from localized to system-spanning scales under external shear, the underlying mechanisms driving this evolution remain poorly understood. In this study, we conduct <em>in situ</em> X-ray computed tomography (CT) triaxial shear tests on Ottawa sand, enabling high-resolution reconstruction of particle-scale kinematics. We identify active clusters characterized by intense nonaffine motion and systematically track their spatiotemporal evolution throughout the entire shearing process. By integrating structural and dynamic attributes of these clusters, we introduce a metric termed adaptability to quantify their resilience and persistence under shear. We demonstrate that, analogous to natural selection in ecological systems, clusters with higher adaptability are more likely to survive, proliferate, and merge with neighboring clusters. This self-reinforcing process enhances the overall adaptability of the granular system and governs the development of shear localization in dense assemblies. Our work provides the first experimental characterization of dynamic heterogeneity in irregular granular materials and offers a novel perspective on the underlying mechanisms governing shear localization, with broad implications for the study of granular materials.</div></div>","PeriodicalId":340,"journal":{"name":"International Journal of Plasticity","volume":"195 ","pages":"Article 104532"},"PeriodicalIF":12.8,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145383073","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 : 2025-12-01Epub Date: 2025-10-22DOI: 10.1016/j.ijplas.2025.104512
Xiaofeng Fan , Yizhuang Li , Jikui Liu , Mingxin Huang , Wei Xu
Utilizing κ-carbide precipitation offers a promising strengthening approach for austenitic lightweight steels. However, coarse intragranular and grain-boundary κ-carbides formed during aging typically promote dynamic slip band localization, reducing work-hardening rates and even triggering brittle fracture. Here, we present an austenitic lightweight steel with a dual-heterogeneous lamellar microstructure, achieved via κ-carbide–mediated recrystallization. After a short, measured high-temperature exposure, heterogeneous nucleation and incomplete dissolution of κ-carbides during recrystallization create a multi-scale precipitate-strengthened hetero-lamellar grain structure. This structure promotes extensive dislocation proliferation, thereby maintaining high strain hardening even at elevated stress levels. Coordinated deformation is facilitated by strain partitioning across multi-level soft/hard domains, while hierarchical shear deformation of κ-carbides progressively relieves interfacial stress concentrations. Additionally, nanoscale local chemical order clusters further elevate the matrix strength to critical levels, activating supplementary twinning-induced plasticity. This strategy resolves the longstanding conflict between κ-carbide strengthening and ductility, achieving an exceptional synergy of properties: ultra-high yield strength (1.1 GPa), ultimate tensile strength (1.32 GPa), remarkable elongation (46 %), and sustained high work-hardening capability. Our work offers a new approach for overcoming the strength-ductility trade-off in precipitation-strengthened austenitic steels and provides guidance for producing next-generation ultra-strong lightweight alloys via spatially engineered heterostructures.
{"title":"κ-carbide induced dual-heterogeneous structure pursuing ultrahigh strength and ductility in lightweight steels","authors":"Xiaofeng Fan , Yizhuang Li , Jikui Liu , Mingxin Huang , Wei Xu","doi":"10.1016/j.ijplas.2025.104512","DOIUrl":"10.1016/j.ijplas.2025.104512","url":null,"abstract":"<div><div>Utilizing κ-carbide precipitation offers a promising strengthening approach for austenitic lightweight steels. However, coarse intragranular and grain-boundary κ-carbides formed during aging typically promote dynamic slip band localization, reducing work-hardening rates and even triggering brittle fracture. Here, we present an austenitic lightweight steel with a dual-heterogeneous lamellar microstructure, achieved via κ-carbide–mediated recrystallization. After a short, measured high-temperature exposure, heterogeneous nucleation and incomplete dissolution of κ-carbides during recrystallization create a multi-scale precipitate-strengthened hetero-lamellar grain structure. This structure promotes extensive dislocation proliferation, thereby maintaining high strain hardening even at elevated stress levels. Coordinated deformation is facilitated by strain partitioning across multi-level soft/hard domains, while hierarchical shear deformation of κ-carbides progressively relieves interfacial stress concentrations. Additionally, nanoscale local chemical order clusters further elevate the matrix strength to critical levels, activating supplementary twinning-induced plasticity. This strategy resolves the longstanding conflict between κ-carbide strengthening and ductility, achieving an exceptional synergy of properties: ultra-high yield strength (1.1 GPa), ultimate tensile strength (1.32 GPa), remarkable elongation (46 %), and sustained high work-hardening capability. Our work offers a new approach for overcoming the strength-ductility trade-off in precipitation-strengthened austenitic steels and provides guidance for producing next-generation ultra-strong lightweight alloys via spatially engineered heterostructures.</div></div>","PeriodicalId":340,"journal":{"name":"International Journal of Plasticity","volume":"195 ","pages":"Article 104512"},"PeriodicalIF":12.8,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145382399","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 : 2025-12-01Epub Date: 2025-11-03DOI: 10.1016/j.ijplas.2025.104533
Jiawen Zhang , Zhangtao Li , Yuwei Zhang , Hendrik Holz , James P. Best , Oliver Preuß , Zhenyong Chen , Yinan Cui , Xufei Fang , Wenjun Lu
Dislocations in ceramics have recently gained renewed research interest, in contrast to the traditional belief that ceramics are inherently brittle. Understanding dislocation mechanics in representative oxides is beneficial for effective dislocation engineering. Here, we use MgO single crystals with mechanically seeded dislocation densities from ∼1012 to ∼1015 m-2 to investigate the mechanical behavior such as yield and fracture. Micro-pillar compression tests reveal a dislocation density dependent yield strength, mediated by the varying dominating dislocation mechanisms from nucleation to multiplication/motion. In situ TEM compression measurements highlight the dislocation-seeded samples can achieve a much-improved compressive plastic strain beyond ∼70%, with a high yield strength of ∼2.35 GPa (diameter of ∼400 nm), indicating size effect. Complementary bulk compression tests, along with digital image correlation (DIC), demonstrate a consistent dislocation-mediated deformation and a notable size effect, with bulk samples exhibiting much reduced yield strength (∼120 MPa) compared to the nano-/micro-pillars. Using three-dimensional Discrete Dislocation Dynamics (3D-DDD) simulation, we further qualitatively analyze the collective dislocation activities (slip events) and work hardening during compression. This study provides new insights into dislocation-mediated plasticity in MgO, across different length scales, by systematically tuning dislocation density.
{"title":"Scale-bridging dislocation plasticity in MgO at room temperature","authors":"Jiawen Zhang , Zhangtao Li , Yuwei Zhang , Hendrik Holz , James P. Best , Oliver Preuß , Zhenyong Chen , Yinan Cui , Xufei Fang , Wenjun Lu","doi":"10.1016/j.ijplas.2025.104533","DOIUrl":"10.1016/j.ijplas.2025.104533","url":null,"abstract":"<div><div>Dislocations in ceramics have recently gained renewed research interest, in contrast to the traditional belief that ceramics are inherently brittle. Understanding dislocation mechanics in representative oxides is beneficial for effective dislocation engineering. Here, we use MgO single crystals with mechanically seeded dislocation densities from ∼10<sup>12</sup> to ∼10<sup>15</sup> m<sup>-2</sup> to investigate the mechanical behavior such as yield and fracture. Micro-pillar compression tests reveal a dislocation density dependent yield strength, mediated by the varying dominating dislocation mechanisms from nucleation to multiplication/motion. <em>In situ</em> TEM compression measurements highlight the dislocation-seeded samples can achieve a much-improved compressive plastic strain beyond ∼70%, with a high yield strength of ∼2.35 GPa (diameter of ∼400 nm), indicating size effect. Complementary bulk compression tests, along with digital image correlation (DIC), demonstrate a consistent dislocation-mediated deformation and a notable size effect, with bulk samples exhibiting much reduced yield strength (∼120 MPa) compared to the nano-/micro-pillars. Using three-dimensional Discrete Dislocation Dynamics (3D-DDD) simulation, we further qualitatively analyze the collective dislocation activities (slip events) and work hardening during compression. This study provides new insights into dislocation-mediated plasticity in MgO, across different length scales, by systematically tuning dislocation density.</div></div>","PeriodicalId":340,"journal":{"name":"International Journal of Plasticity","volume":"195 ","pages":"Article 104533"},"PeriodicalIF":12.8,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145428020","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 : 2025-12-01Epub Date: 2025-10-13DOI: 10.1016/j.ijplas.2025.104505
Peiyuan Ma , Hang Wang , Hao Zhang , Yuliang Lin , Zihan Zhang , Xu Zhang , Rong Chen
High/medium-entropy alloys (HEAs/MEAs) are gaining attention for their superior mechanical properties, especially in applications that require high strength and impact resistance. Among these, body-centered cubic (BCC) refractory HEAs are notable for their high-temperature stability and mechanical strength. However, achieving an optimal balance between strength and ductility remains challenging. This study focuses on TiZrNbV BCC-HEA, which exhibits not only impressive strength (yield strength > 1 GPa) but also good ductility (∼9 % uniform elongation). Its plastic deformation and strengthening mechanisms are investigated through uniaxial tensile tests, cyclic load-unload-reload tests, and stress-relaxation tests. Key to understanding its mechanical behavior is the evolution of dislocation structures, including mobile dislocations, geometrically necessary dislocations (GNDs), and statistically stored dislocations (SSDs). The Kocks-Mecking model is employed to examine hardening mechanisms. At low strains, heterogeneous deformation-induced (HDI) hardening dominates, while forest dislocation hardening prevails at higher strains. This work sheds light on the interplay of dislocation density evolution and hardening mechanisms in achieving the high strength and ductility of alloys. These mechanisms of dislocation synergistic evolution and strengthening are valuable for designing advanced alloys with optimized mechanical properties, paving the way for high-performance materials in extreme environments like aerospace, automotive, and energy industries.
{"title":"The mechanism of multi-component dislocation synergistic evolution and material strengthening in the as-cast TiZrNbV refractory high-entropy alloy","authors":"Peiyuan Ma , Hang Wang , Hao Zhang , Yuliang Lin , Zihan Zhang , Xu Zhang , Rong Chen","doi":"10.1016/j.ijplas.2025.104505","DOIUrl":"10.1016/j.ijplas.2025.104505","url":null,"abstract":"<div><div>High/medium-entropy alloys (HEAs/MEAs) are gaining attention for their superior mechanical properties, especially in applications that require high strength and impact resistance. Among these, body-centered cubic (BCC) refractory HEAs are notable for their high-temperature stability and mechanical strength. However, achieving an optimal balance between strength and ductility remains challenging. This study focuses on TiZrNbV BCC-HEA, which exhibits not only impressive strength (yield strength > 1 GPa) but also good ductility (∼9 % uniform elongation). Its plastic deformation and strengthening mechanisms are investigated through uniaxial tensile tests, cyclic load-unload-reload tests, and stress-relaxation tests. Key to understanding its mechanical behavior is the evolution of dislocation structures, including mobile dislocations, geometrically necessary dislocations (GNDs), and statistically stored dislocations (SSDs). The Kocks-Mecking model is employed to examine hardening mechanisms. At low strains, heterogeneous deformation-induced (HDI) hardening dominates, while forest dislocation hardening prevails at higher strains. This work sheds light on the interplay of dislocation density evolution and hardening mechanisms in achieving the high strength and ductility of alloys. These mechanisms of dislocation synergistic evolution and strengthening are valuable for designing advanced alloys with optimized mechanical properties, paving the way for high-performance materials in extreme environments like aerospace, automotive, and energy industries.</div></div>","PeriodicalId":340,"journal":{"name":"International Journal of Plasticity","volume":"195 ","pages":"Article 104505"},"PeriodicalIF":12.8,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145283516","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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