Pub Date : 2026-01-31DOI: 10.1016/j.ijplas.2026.104628
Ji Lin, Wuyang Zhao, Rui Xiao
{"title":"A three-dimensional shear transformation zone theory for glassy polymers","authors":"Ji Lin, Wuyang Zhao, Rui Xiao","doi":"10.1016/j.ijplas.2026.104628","DOIUrl":"https://doi.org/10.1016/j.ijplas.2026.104628","url":null,"abstract":"","PeriodicalId":340,"journal":{"name":"International Journal of Plasticity","volume":"93 1","pages":""},"PeriodicalIF":9.8,"publicationDate":"2026-01-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146095707","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 : 2026-01-29DOI: 10.1016/j.ijplas.2026.104627
Farhan Ashraf, Nicolò Grilli, Chen Liu, Michael Salvini, Catrin M. Davies, Christopher E. Truman, Mahmoud Mostafavi, David Knowles
{"title":"Investigating Creep Damage Initiation at the Mesoscale Using High-Resolution Electron Microscopy, Crystal Plasticity Modelling, and a Classification Algorithm","authors":"Farhan Ashraf, Nicolò Grilli, Chen Liu, Michael Salvini, Catrin M. Davies, Christopher E. Truman, Mahmoud Mostafavi, David Knowles","doi":"10.1016/j.ijplas.2026.104627","DOIUrl":"https://doi.org/10.1016/j.ijplas.2026.104627","url":null,"abstract":"","PeriodicalId":340,"journal":{"name":"International Journal of Plasticity","volume":"30 1","pages":""},"PeriodicalIF":9.8,"publicationDate":"2026-01-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146072352","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 : 2026-01-28DOI: 10.1016/j.ijplas.2026.104625
Jianguo Li, Tianqi Zhou, Xinjie Yang, Zhongbin Tang, Tao Suo
Refractory high-entropy alloys (RHEAs) hold great promise for impact engineering due to their superior dynamic mechanical properties. However, the limited understanding of the adiabatic shear instability mechanism in these alloys restricts their effective design and application for enhanced impact performance. This study provides a comprehensive investigation into the mechanical responses of near-equiatomic TiZrHfNbTa RHEA across a wide range of temperature and strain rate. Upon impact compression to substantial strains, adiabatic shear bands (ASBs) emerge as the predominant failure mode. Utilizing an in situ high-speed “force-heat-deformation” synchronous testing system based on the split Hopkinson pressure bar, we have meticulously characterized the initiation and propagation of ASBs. Our work clearly elucidates the pronounced adiabatic temperature rise associated with localized shear deformation. Moreover, through quasi-in situ microstructural evolution analysis, we have delineated the microscopic evolution wherein local deformation sites expand and interconnect along the most deformable grains, ultimately leading to the formation of through-shear zones. Additionally, we have uncovered the micro-mechanism by which dynamic recrystallization (DRX) within these shear zones induces plastic instability. To quantitatively decouple the specific contributions of thermal softening and dynamic recrystallization softening to dynamic instability, we have developed a crystal plasticity mechanical constitutive model to accurately capture the mechanical responses of the RHEA by incorporating the influence of dynamic recrystallization evolution. Our findings highlight the crucial role of DRX softening in driving local shear instability in the RHEA. By combining full-process microcharacterization with mesoscale crystal plasticity finite element simulations, this work offers a precise analysis of the formation mechanism underlying the dynamic instability in BCC RHEA. This research is expected to provide a robust theoretical foundation for the future design of advanced metallic materials with enhanced impact performance.
{"title":"Adiabatic shear instability mechanisms in BCC TiHfZrTaNb high entropy alloy: insights from microscale experiments and simulations","authors":"Jianguo Li, Tianqi Zhou, Xinjie Yang, Zhongbin Tang, Tao Suo","doi":"10.1016/j.ijplas.2026.104625","DOIUrl":"https://doi.org/10.1016/j.ijplas.2026.104625","url":null,"abstract":"Refractory high-entropy alloys (RHEAs) hold great promise for impact engineering due to their superior dynamic mechanical properties. However, the limited understanding of the adiabatic shear instability mechanism in these alloys restricts their effective design and application for enhanced impact performance. This study provides a comprehensive investigation into the mechanical responses of near-equiatomic TiZrHfNbTa RHEA across a wide range of temperature and strain rate. Upon impact compression to substantial strains, adiabatic shear bands (ASBs) emerge as the predominant failure mode. Utilizing an <em>in situ</em> high-speed “force-heat-deformation” synchronous testing system based on the split Hopkinson pressure bar, we have meticulously characterized the initiation and propagation of ASBs. Our work clearly elucidates the pronounced adiabatic temperature rise associated with localized shear deformation. Moreover, through quasi-<em>in situ</em> microstructural evolution analysis, we have delineated the microscopic evolution wherein local deformation sites expand and interconnect along the most deformable grains, ultimately leading to the formation of through-shear zones. Additionally, we have uncovered the micro-mechanism by which dynamic recrystallization (DRX) within these shear zones induces plastic instability. To quantitatively decouple the specific contributions of thermal softening and dynamic recrystallization softening to dynamic instability, we have developed a crystal plasticity mechanical constitutive model to accurately capture the mechanical responses of the RHEA by incorporating the influence of dynamic recrystallization evolution. Our findings highlight the crucial role of DRX softening in driving local shear instability in the RHEA. By combining full-process microcharacterization with mesoscale crystal plasticity finite element simulations, this work offers a precise analysis of the formation mechanism underlying the dynamic instability in BCC RHEA. This research is expected to provide a robust theoretical foundation for the future design of advanced metallic materials with enhanced impact performance.","PeriodicalId":340,"journal":{"name":"International Journal of Plasticity","volume":"77 1","pages":""},"PeriodicalIF":9.8,"publicationDate":"2026-01-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146056096","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 : 2026-01-23DOI: 10.1016/j.ijplas.2026.104624
Wenjie Lu , Bin Huang , Rui Hu , Xu-Sheng Yang
Activating additional strain-hardening mechanisms is essential to achieve superior strain hardening capacity and strength-ductility synergy in precipitation-hardened alloys. In this work, we introduce a synergistic strategy that combines dual-heterogeneous structures (DHS) with the transformation-induced plasticity (TRIP) effect in a precipitation-hardened medium-entropy alloy (MEA), thereby enabling multiple strain-hardening mechanisms for the exceptional strength-ductility combination. The tailored alloy showcases a high yield strength of ∼ 1290 MPa, an ultimate tensile strength of ∼ 1737 MPa, and an excellent fracture elongation of ∼ 36.9% at ambient temperature, exhibiting a ∼ 162% increase in yield strength without compromising uniform ductility, compared to its single-phase solid solution counterpart. Microstructural analyses reveal that the enhanced yield strength stems primarily from precipitation hardening and extra hetero-deformation induced (HDI) hardening. Furthermore, plastic deformation mechanism investigations demonstrate that the remarkable work-hardening capacity (> 3 GPa) results from the combined effects of dynamically enhanced HDI hardening and the activated TRIP effect during tensile deformation. These multiple and sustained strain-hardening mechanisms underpin the alloy’s exceptional strength-ductility synergy. Our study provides a promising strategy for designing high-performance structural materials.
{"title":"Obtaining superior strength-ductility synergy properties in a medium-entropy alloy via dual heterogeneous and TRIP effects","authors":"Wenjie Lu , Bin Huang , Rui Hu , Xu-Sheng Yang","doi":"10.1016/j.ijplas.2026.104624","DOIUrl":"10.1016/j.ijplas.2026.104624","url":null,"abstract":"<div><div>Activating additional strain-hardening mechanisms is essential to achieve superior strain hardening capacity and strength-ductility synergy in precipitation-hardened alloys. In this work, we introduce a synergistic strategy that combines dual-heterogeneous structures (DHS) with the transformation-induced plasticity (TRIP) effect in a precipitation-hardened medium-entropy alloy (MEA), thereby enabling multiple strain-hardening mechanisms for the exceptional strength-ductility combination. The tailored alloy showcases a high yield strength of ∼ 1290 MPa, an ultimate tensile strength of ∼ 1737 MPa, and an excellent fracture elongation of ∼ 36.9% at ambient temperature, exhibiting a ∼ 162% increase in yield strength without compromising uniform ductility, compared to its single-phase solid solution counterpart. Microstructural analyses reveal that the enhanced yield strength stems primarily from precipitation hardening and extra hetero-deformation induced (HDI) hardening. Furthermore, plastic deformation mechanism investigations demonstrate that the remarkable work-hardening capacity (> 3 GPa) results from the combined effects of dynamically enhanced HDI hardening and the activated TRIP effect during tensile deformation. These multiple and sustained strain-hardening mechanisms underpin the alloy’s exceptional strength-ductility synergy. Our study provides a promising strategy for designing high-performance structural materials.</div></div>","PeriodicalId":340,"journal":{"name":"International Journal of Plasticity","volume":"198 ","pages":"Article 104624"},"PeriodicalIF":12.8,"publicationDate":"2026-01-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146033004","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 : 2026-01-21DOI: 10.1016/j.ijplas.2026.104623
Yongzhen Wang , Shengyu Duan , Chunwang He , Ying Li , Qinglei Zeng , Daining Fang
Mechanical metamaterials have attracted considerable attention due to their exceptional mechanical properties, making them promising candidates for advanced structural applications. However, accurate and efficient prediction of the history-dependent, nonlinear mechanical behavior of elastoplastic metamaterial structures remains challenging. In this work, we propose a data-driven elastoplastic super element (DD-EPSE) framework to model the elastoplastic response of metamaterials. Unlike traditional representative volume element (RVE)-based homogenization that relies on scale separation and equivalent stress-strain relationships, DD-EPSE treats each unit cell as a structural element governed by force-displacement relationships at control points, with nodal forces serving as internal variables. After eliminating rigid-body motions, the incremental force-displacement response is captured by a specially designed artificial neural network framework, which enforces objectivity and equilibrium. A support vector machine (SVM) classifier is incorporated to identify plastic zones within metastructures. The method is validated through extensive numerical simulations and experiments on triply periodic minimal surface (TPMS)-based metamaterials under diverse loading conditions. Results demonstrate that DD-EPSE accurately predicts the force-displacement response and plasticity distribution of large-scale metastructures, while reducing computational cost by several orders of magnitude compared to direct numerical simulations. In addition, its applicability to other metamaterial topologies is validated through transfer learning, exemplified by beam-lattice structures. The DD-EPSE framework provides an efficient tool for modeling and designing of mechanical metamaterials with history-dependent nonlinear behavior.
{"title":"A data-driven elastoplastic super element method for multiscale modeling of history-dependent responses in metamaterials","authors":"Yongzhen Wang , Shengyu Duan , Chunwang He , Ying Li , Qinglei Zeng , Daining Fang","doi":"10.1016/j.ijplas.2026.104623","DOIUrl":"10.1016/j.ijplas.2026.104623","url":null,"abstract":"<div><div>Mechanical metamaterials have attracted considerable attention due to their exceptional mechanical properties, making them promising candidates for advanced structural applications. However, accurate and efficient prediction of the history-dependent, nonlinear mechanical behavior of elastoplastic metamaterial structures remains challenging. In this work, we propose a data-driven elastoplastic super element (DD-EPSE) framework to model the elastoplastic response of metamaterials. Unlike traditional representative volume element (RVE)-based homogenization that relies on scale separation and equivalent stress-strain relationships, DD-EPSE treats each unit cell as a structural element governed by force-displacement relationships at control points, with nodal forces serving as internal variables. After eliminating rigid-body motions, the incremental force-displacement response is captured by a specially designed artificial neural network framework, which enforces objectivity and equilibrium. A support vector machine (SVM) classifier is incorporated to identify plastic zones within metastructures. The method is validated through extensive numerical simulations and experiments on triply periodic minimal surface (TPMS)-based metamaterials under diverse loading conditions. Results demonstrate that DD-EPSE accurately predicts the force-displacement response and plasticity distribution of large-scale metastructures, while reducing computational cost by several orders of magnitude compared to direct numerical simulations. In addition, its applicability to other metamaterial topologies is validated through transfer learning, exemplified by beam-lattice structures. The DD-EPSE framework provides an efficient tool for modeling and designing of mechanical metamaterials with history-dependent nonlinear behavior.</div></div>","PeriodicalId":340,"journal":{"name":"International Journal of Plasticity","volume":"198 ","pages":"Article 104623"},"PeriodicalIF":12.8,"publicationDate":"2026-01-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146033006","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 : 2026-01-21DOI: 10.1016/j.ijplas.2026.104622
Yongmiao Liu, Yusheng Wang, Mingliang Wang, Yiping Lu
Refractory high-entropy alloys (RHEAs) demonstrate exceptional resistance to softening at elevated temperatures, positioning them as leading candidates for high-temperature structural applications. Nevertheless, state-of-the-art RHEAs still exhibit elevated density and inherent room-temperature brittleness, thereby constraining their industrial deployment. This study systematically investigates a lightweight Ti55Zr10V15Nb10Al10 refractory high-entropy alloy (RHEA) (ρ ≈ 5.3 g/cm³) strengthened with Y2O3 nanoparticles. The alloy achieves an exceptional yield strength of ∼1370 MPa alongside a tensile ductility of ∼15% (with ∼7% uniform elongation), significantly surpassing both its base alloy and most reported RHEAs. This superior strength–ductility synergy originates from semi-coherent Y2O3/BCC interfaces, which provide effective Orowan strengthening while promoting extensive activation of multi-slip deformation dominated by non-screw dislocations. This atypical deformation mode sustains strain hardening and retains ductility in the BCC matrix.This work demonstrates that the introduction of coherent ceramic nanoparticles is a potent strategy to bypass the strength-ductility trade-off in RHEAs.
{"title":"Tailoring lightweight refractory high-entropy alloys via Y2O3 additions: Achieving >1.3 GPa yield strength with retained ductility","authors":"Yongmiao Liu, Yusheng Wang, Mingliang Wang, Yiping Lu","doi":"10.1016/j.ijplas.2026.104622","DOIUrl":"10.1016/j.ijplas.2026.104622","url":null,"abstract":"<div><div>Refractory high-entropy alloys (RHEAs) demonstrate exceptional resistance to softening at elevated temperatures, positioning them as leading candidates for high-temperature structural applications. Nevertheless, state-of-the-art RHEAs still exhibit elevated density and inherent room-temperature brittleness, thereby constraining their industrial deployment. This study systematically investigates a lightweight Ti<sub>55</sub>Zr<sub>10</sub>V<sub>15</sub>Nb<sub>10</sub>Al<sub>10</sub> refractory high-entropy alloy (RHEA) (ρ ≈ 5.3 g/cm³) strengthened with Y<sub>2</sub>O<sub>3</sub> nanoparticles. The alloy achieves an exceptional yield strength of ∼1370 MPa alongside a tensile ductility of ∼15% (with ∼7% uniform elongation), significantly surpassing both its base alloy and most reported RHEAs. This superior strength–ductility synergy originates from semi-coherent Y<sub>2</sub>O<sub>3</sub>/BCC interfaces, which provide effective Orowan strengthening while promoting extensive activation of multi-slip deformation dominated by non-screw dislocations. This atypical deformation mode sustains strain hardening and retains ductility in the BCC matrix.This work demonstrates that the introduction of coherent ceramic nanoparticles is a potent strategy to bypass the strength-ductility trade-off in RHEAs.</div></div>","PeriodicalId":340,"journal":{"name":"International Journal of Plasticity","volume":"198 ","pages":"Article 104622"},"PeriodicalIF":12.8,"publicationDate":"2026-01-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146014423","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 : 2026-01-20DOI: 10.1016/j.ijplas.2026.104621
Haipeng Li , Yipeng Gao , Yizhen Li , Tao Yu , Chunfeng Du , Yongsi Wei , Yuchao Song , Hui-Yuan Wang
The mechanical behavior of polycrystalline metals is profoundly influenced by the interaction between deformation twins and grain boundaries (GBs), which concurrently induces strengthening and accommodates plastic strain. Particularly in hexagonal close-packed metals, the coexistence and competition of multiple twinning modes at diverse GBs can lead to interface/junction incompatibilities through complex defect reactions. These incompatibilities, mediated by the formation of dislocations and disclinations, result in local stress concentrations that govern subsequent hardening and damage phenomena. However, a theoretical framework for quantitatively determining the stress fields resulting from all types of twin-GB reactions remains underdeveloped. Here, we bridge this gap by integrating topological defect analysis with phase-field simulations to establish a general approach for calculating the defect structures and internal stresses arising from twin-GB reactions. Taking -Ti as a representative case, we systematically analyze the distributions of dislocations, disclinations, and local stresses across a broad range of twin-GB reactions. Our analysis reveals that twin transmission—a key accommodation mechanism—is governed by the minimization of residual defects and the associated stress concentration from twin-GB reactions. This principle is validated by our phase-field simulations and electron backscatter diffraction characterizations. This work establishes a quantitative, mechanism-based framework for predicting local stress concentrations and plastic accommodation in polycrystalline materials, providing fundamental insights into the role of twin-GB interactions in the macroscopic mechanical response.
{"title":"Topological defect analysis and phase field study of disclination-assisted twin-grain boundary reactions in HCP-Ti polycrystals","authors":"Haipeng Li , Yipeng Gao , Yizhen Li , Tao Yu , Chunfeng Du , Yongsi Wei , Yuchao Song , Hui-Yuan Wang","doi":"10.1016/j.ijplas.2026.104621","DOIUrl":"10.1016/j.ijplas.2026.104621","url":null,"abstract":"<div><div>The mechanical behavior of polycrystalline metals is profoundly influenced by the interaction between deformation twins and grain boundaries (GBs), which concurrently induces strengthening and accommodates plastic strain. Particularly in hexagonal close-packed metals, the coexistence and competition of multiple twinning modes at diverse GBs can lead to interface/junction incompatibilities through complex defect reactions. These incompatibilities, mediated by the formation of dislocations and disclinations, result in local stress concentrations that govern subsequent hardening and damage phenomena. However, a theoretical framework for quantitatively determining the stress fields resulting from all types of twin-GB reactions remains underdeveloped. Here, we bridge this gap by integrating topological defect analysis with phase-field simulations to establish a general approach for calculating the defect structures and internal stresses arising from twin-GB reactions. Taking <span><math><mi>α</mi></math></span>-Ti as a representative case, we systematically analyze the distributions of dislocations, disclinations, and local stresses across a broad range of twin-GB reactions. Our analysis reveals that twin transmission—a key accommodation mechanism—is governed by the minimization of residual defects and the associated stress concentration from twin-GB reactions. This principle is validated by our phase-field simulations and electron backscatter diffraction characterizations. This work establishes a quantitative, mechanism-based framework for predicting local stress concentrations and plastic accommodation in polycrystalline materials, providing fundamental insights into the role of twin-GB interactions in the macroscopic mechanical response.</div></div>","PeriodicalId":340,"journal":{"name":"International Journal of Plasticity","volume":"198 ","pages":"Article 104621"},"PeriodicalIF":12.8,"publicationDate":"2026-01-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146014424","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 : 2026-01-15DOI: 10.1016/j.ijplas.2026.104613
Lin Guo , Jiaxing Wu , Ji Gu , Dechuang Zhang , Cheng Ma , Yilong Dai , Jianguo Lin , Ian Baker , Min Song
Twinning and martensitic transformations are well-understood under monotonic loading, yet how stress reversal and the associated kinematic reversibility, inherent to cyclic deformation, affects these mechanisms remains insufficiently understood. Here, we systematically investigate the microstructural evolution of a metastable high entropy alloy Fe60Mn12Cr12Ni8Si8 under cyclic tension-compression (CTC) loading. Multi-scale characterizations reveal that the cyclic stress reversal fundamentally alters the transformation pathway compared to the monotonic tension. The initial, undeformed material consists of a face-centered cubic γ phase. Monotonic tension primarily activates deformation-induced martensitic transformation, whereas CTC produces markedly different microstructural pathways depending on strain amplitude. At a low strain amplitude (0.5%), short-range glide of Shockley partial dislocations promotes extensive formation of HCP ε-martensite (a fraction of ∼68.3%). In contrast, high-strain-amplitude CTC loading (2.0%) activates an abnormal transformation-mediated twinning mechanism. This process, driven by the reversible motion of Shockley partial dislocation within confined ε-martensite, leads to a refined γ/γtwin/ε nano-laminate structure with a spacing of ∼2.6 nm. Furthermore, we identify unconventional polymorphic transformation pathways accommodating the high local stress concentrations: (i) nucleation of body-centered cubic α′-martensite at a specific interface where the two γ phases maintain an 86° angle between their respective planes, and (ii) a direct γ to body-centered tetragonal α-martensite transition via continuous lattice shearing along . These mechanisms are attributed to the unique stress accommodation requirements in the highly confined nano-laminates. The resulting hierarchical microstructure not only relieves local stress concentrations but also contributes to the good cyclic durability. Overall, these findings establish an atomistic mechanistic link between cyclic reversibility and transformation/twinning pathway selection, and suggest a processing-enabled route to engineer heterogeneous γ/γtwin/ε nano-laminate structure in bulk metastable alloys at room temperature.
{"title":"Abnormal twinning mechanisms and martensitic transformation in Fe60Mn12Cr12Ni8Si8 high entropy alloy under cyclic tension-compression loading","authors":"Lin Guo , Jiaxing Wu , Ji Gu , Dechuang Zhang , Cheng Ma , Yilong Dai , Jianguo Lin , Ian Baker , Min Song","doi":"10.1016/j.ijplas.2026.104613","DOIUrl":"10.1016/j.ijplas.2026.104613","url":null,"abstract":"<div><div>Twinning and martensitic transformations are well-understood under monotonic loading, yet how stress reversal and the associated kinematic reversibility, inherent to cyclic deformation, affects these mechanisms remains insufficiently understood. Here, we systematically investigate the microstructural evolution of a metastable high entropy alloy Fe<sub>60</sub>Mn<sub>12</sub>Cr<sub>12</sub>Ni<sub>8</sub>Si<sub>8</sub> under cyclic tension-compression (CTC) loading. Multi-scale characterizations reveal that the cyclic stress reversal fundamentally alters the transformation pathway compared to the monotonic tension. The initial, undeformed material consists of a face-centered cubic γ phase. Monotonic tension primarily activates deformation-induced martensitic transformation, whereas CTC produces markedly different microstructural pathways depending on strain amplitude. At a low strain amplitude (0.5%), short-range glide of Shockley partial dislocations promotes extensive formation of HCP ε-martensite (a fraction of ∼68.3%). In contrast, high-strain-amplitude CTC loading (2.0%) activates an abnormal transformation-mediated twinning mechanism. This process, driven by the reversible motion of Shockley partial dislocation within confined ε-martensite, leads to a refined γ/γ<sub>twin</sub>/ε nano-laminate structure with a spacing of ∼2.6 nm. Furthermore, we identify unconventional polymorphic transformation pathways accommodating the high local stress concentrations: (i) nucleation of body-centered cubic α′-martensite at a specific interface where the two γ phases maintain an 86° angle between their respective <span><math><msub><mrow><mo>(</mo><mrow><mn>11</mn><mover><mn>1</mn><mo>¯</mo></mover></mrow><mo>)</mo></mrow><mi>γ</mi></msub></math></span> planes, and (ii) a direct γ to body-centered tetragonal α-martensite transition via continuous lattice shearing along <span><math><mrow><mrow><mo>(</mo><mn>111</mn><mo>)</mo></mrow><msub><mrow><mo>[</mo><mrow><mn>11</mn><mover><mn>2</mn><mo>¯</mo></mover></mrow><mo>]</mo></mrow><mi>γ</mi></msub></mrow></math></span>. These mechanisms are attributed to the unique stress accommodation requirements in the highly confined nano-laminates. The resulting hierarchical microstructure not only relieves local stress concentrations but also contributes to the good cyclic durability. Overall, these findings establish an atomistic mechanistic link between cyclic reversibility and transformation/twinning pathway selection, and suggest a processing-enabled route to engineer heterogeneous γ/γ<sub>twin</sub>/ε nano-laminate structure in bulk metastable alloys at room temperature.</div></div>","PeriodicalId":340,"journal":{"name":"International Journal of Plasticity","volume":"198 ","pages":"Article 104613"},"PeriodicalIF":12.8,"publicationDate":"2026-01-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145993424","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 : 2026-01-15DOI: 10.1016/j.ijplas.2026.104610
Yanxiong Liu , Han Zhang , Lin Hua , Feng Huang , Kaisheng Ji , Yizhe Chen , Junnan Mao
Ti-6Al-4 V alloys have attracted increasing attention as candidates to meet targets for lightweight applications in the automotive, aerospace and other industries. To improve the plastic deformation capacity and mechanical properties of deformed parts, this paper proposes a forming process under superimposed hydrostatic pressure. Ti-6Al-4 V alloys were subjected to compression under liquid at a pressure of 175 MPa, which caused superimposed hydrostatic pressure during the compression process. This study revealed the deformation behavior and microstructural evolution of Ti-6Al-4 V alloys under such loading conditions for the first time through experimental, simulation and theoretical analyses. Multiscale characterization (SEM/XRD/TEM) reveals that hydrostatic pressure induces activation of {} and {} α-twins to accommodate deformation, the formation of coherent α/β interfaces and a nonrandom V distribution in the α phase. In comparison to the normal-pressure compression sample, the ultimate compressive strength, hardness, and compression ratio were only 1229.9 MPa, 294.1 HV, and 35%, respectively. The high-pressure compression sample exhibits a superior combination of strength, as evidenced by its ultimate compressive strength (2004.9 MPa), hardness (364.8 HV), and plasticity (42.5% compression ratio). The synergy is attributed to three coupled mechanisms under high pressure: twinning-induced plasticity, interface strengthening and short-range ordering strengthening. Furthermore, theoretical geometrical phase analysis and crystal plasticity simulations reveal that high pressure decreases the stress in the α phase. The resulting significant improvement in both tensile and compressive strains can lead to the formation of a high density of twins. Concurrently, it has been demonstrated to increase the resistance of the β phase to stress, thereby preventing the β phase cracking that is frequently observed in normal pressure compression. These results provide a promising pathway for overcoming the severe engineering challenges caused by the low room-temperature plasticity of Ti-6Al-4 V alloys.
{"title":"Deformation behavior and microstructural evolution of Ti-6Al-4 V alloy under compression with confining pressure","authors":"Yanxiong Liu , Han Zhang , Lin Hua , Feng Huang , Kaisheng Ji , Yizhe Chen , Junnan Mao","doi":"10.1016/j.ijplas.2026.104610","DOIUrl":"10.1016/j.ijplas.2026.104610","url":null,"abstract":"<div><div>Ti-6Al-4 V alloys have attracted increasing attention as candidates to meet targets for lightweight applications in the automotive, aerospace and other industries. To improve the plastic deformation capacity and mechanical properties of deformed parts, this paper proposes a forming process under superimposed hydrostatic pressure. Ti-6Al-4 V alloys were subjected to compression under liquid at a pressure of 175 MPa, which caused superimposed hydrostatic pressure during the compression process. This study revealed the deformation behavior and microstructural evolution of Ti-6Al-4 V alloys under such loading conditions for the first time through experimental, simulation and theoretical analyses. Multiscale characterization (SEM/XRD/TEM) reveals that hydrostatic pressure induces activation of {<span><math><mrow><mn>10</mn><mover><mn>1</mn><mo>¯</mo></mover><mn>1</mn></mrow></math></span>} and {<span><math><mrow><mn>10</mn><mover><mn>1</mn><mo>¯</mo></mover><mn>2</mn></mrow></math></span>} α-twins to accommodate deformation, the formation of coherent α/β interfaces and a nonrandom V distribution in the α phase. In comparison to the normal-pressure compression sample, the ultimate compressive strength, hardness, and compression ratio were only 1229.9 MPa, 294.1 HV, and 35%, respectively. The high-pressure compression sample exhibits a superior combination of strength, as evidenced by its ultimate compressive strength (2004.9 MPa), hardness (364.8 HV), and plasticity (42.5% compression ratio). The synergy is attributed to three coupled mechanisms under high pressure: twinning-induced plasticity, interface strengthening and short-range ordering strengthening. Furthermore, theoretical geometrical phase analysis and crystal plasticity simulations reveal that high pressure decreases the stress in the α phase. The resulting significant improvement in both tensile and compressive strains can lead to the formation of a high density of twins. Concurrently, it has been demonstrated to increase the resistance of the β phase to stress, thereby preventing the β phase cracking that is frequently observed in normal pressure compression. These results provide a promising pathway for overcoming the severe engineering challenges caused by the low room-temperature plasticity of Ti-6Al-4 V alloys.</div></div>","PeriodicalId":340,"journal":{"name":"International Journal of Plasticity","volume":"198 ","pages":"Article 104610"},"PeriodicalIF":12.8,"publicationDate":"2026-01-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145995367","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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