International Journal of Plasticity最新文献

{"title":"Superior fatigue response of CoCrNi-based multi-principal element alloy with Mo addition","authors":"Shubham Sisodia ,&nbsp;Akshat Godha ,&nbsp;Chethan Konkati ,&nbsp;Nikhil Suman ,&nbsp;Govind Bajargan ,&nbsp;Surendra Kumar Makenini ,&nbsp;Ankur Chauhan","doi":"10.1016/j.ijplas.2025.104604","DOIUrl":"10.1016/j.ijplas.2025.104604","url":null,"abstract":"<div><div>Single-phase CoCrNi-based multi-principal element alloys (MPEAs) are recognized for their excellent fatigue damage tolerance. To further enhance their performance, a small amount of Mo was introduced into the CoCrNi system, resulting in the Co_35.4Cr_22.9Ni_35.5Mo_6.2 (commercially known as MP35N). This study investigates its tensile and low-cycle fatigue behavior at room temperature. The alloy, with an average grain size of ∼67 µm, exhibits a yield strength of 303 ± 8 MPa, an ultimate tensile strength of 800 ± 7 MPa, and a total-elongation-to-failure of 75 ± 3%. Its pronounced work-hardening and high ductility arise from its low stacking fault energy (SFE), which enables the concurrent activation of planar slip and deformation twinning. Under cyclic loading, the alloy shows pronounced initial cyclic hardening, followed by strain amplitude-dependent responses. Away from fatigue cracks, deformation is governed by planar slip of extended dislocations, whose multiplication and interactions generate sessile stacking-fault nodes and Lomer–Cottrell locks, driving cyclic hardening. At low strain amplitudes (±0.3% and ±0.5%), dislocations remain homogeneously distributed within the grains, with no twinning away from the fatigue cracks. In contrast, at higher strain amplitude (±0.7%), dislocation density increases, accompanied by a growing tendency to rearrange into low-energy structures and localized deformation twinning, as the cyclic peak stresses exceed the critical twinning stress. Surface relief-assisted fatigue cracks predominantly initiate parallel to coherent annealing twin boundaries (ATBs), with fewer occurrences across ATBs, or along/across grain boundaries. This behaviour is governed by slip compatibility and transfer metrics, evaluated through the Taylor factor, elastic stiffness contrast, ATB–loading-axis orientation, Schmid factor, and the Luster–Morris parameter. Near fatigue cracks, high local stresses activate deformation twinning at all strain amplitudes, which is intersected and sheared by shear bands. Twinning contributes to strengthening, while shear bands nucleate within pre-twinned regions, leading to twin bending, necking, detwinning, and the formation of nano-subgrains, which facilitate localized softening. Compared to other CoCrNi-based MPEAs, this Mo-alloyed variant achieves higher peak stresses and comparable or improved fatigue life. These enhancements stem from Mo-induced strengthening and the alloy’s low SFE, which promotes reversible planar slip, suppresses dislocation rearrangement into low-energy structures such as walls, veins, and cells, and amplifies twinning and shear banding near cracks. Collectively, these mechanisms define the overall cyclic stress response, accommodate localised plastic strain, generate tortuous crack paths, and slow crack growth, thereby conferring fatigue resistance that approaches that of dual-phase MPEAs.</div></div>","PeriodicalId":340,"journal":{"name":"International Journal of Plasticity","volume":"197 ","pages":"Article 104604"},"PeriodicalIF":12.8,"publicationDate":"2025-12-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145922260","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}

{"title":"Enhancing the strength and plasticity of laminated aluminum alloy by introducing micron-scale pure aluminum interlayers","authors":"Yufeng Song ,&nbsp;Lijie Wang ,&nbsp;Yuqiang Chen ,&nbsp;Wenhui Liu ,&nbsp;Ziyi Teng ,&nbsp;Qiang Hu ,&nbsp;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":"2025-12-26","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}

{"title":"Revealing fracture-resistant design principles in harmonic-structured high-entropy alloys using quasi in situ experiments and integrated modeling","authors":"Ruo-Fei Yuan ,&nbsp;Yong Zhang ,&nbsp;Yu Zhang ,&nbsp;Bo Dong ,&nbsp;Yong-Ji Wang ,&nbsp;Zhe Zhang ,&nbsp;Tang Gu ,&nbsp;Yun-Fei Jia ,&nbsp;Fu-Zhen Xuan","doi":"10.1016/j.ijplas.2025.104600","DOIUrl":"10.1016/j.ijplas.2025.104600","url":null,"abstract":"<div><div>Harmonic-structured (HS) metallic materials have garnered significant interest owing to their exceptional strength–ductility synergy, yet grain-scale fracture mechanisms remain poorly elucidated, impeding the formulation of predictive strategies for strength–toughness balancing. To address this gap, we fabricated HS CoCrFeMnNi high-entropy alloys with tailored fine-grain (FG) shell fractions. Quasi-in situ tensile experiments monitored via electron backscatter diffraction (EBSD) and crystal plasticity finite element/cohesive zone modeling (CPFEM–CZM) reveal that FG regions exhibit high crack susceptibility due to pronounced strain gradients—particularly at coarse-grain (CG)/FG interfaces and within fine-grained zones—that evolve with strain and intensify stress concentration through deformation incompatibility, thereby promoting preferential crack nucleation and propagation. Conversely, CG regions enable sustained plastic energy dissipation via superior intrinsic deformability. Cracks nucleate and propagate preferentially within FG zones, while CG domains dissipate energy via plasticity and microcracking, diverting energy from primary crack growth. As cracks propagate into CG regions, they activate multiple slip systems, generating strain gradients that increase geometrically necessary dislocation density near crack tips. This elevates back stress, inducing crack blunting and enhancing fracture tolerance. Crucially, an optimal FG fraction (31.4%) prevents premature crack nucleation in FG regions while maintaining strength unattainable in low-FG HS variants, thereby preserving material continuity. This dual-phase synergy ensures superior fracture resistance and strength-toughness balance in HS alloys. Our work elucidates intrinsic fracture resistance mechanisms of HS microstructures and quantifies the effects of FG fraction on damage tolerance, establishing essential microstructural design criteria for advanced metallic materials.</div></div>","PeriodicalId":340,"journal":{"name":"International Journal of Plasticity","volume":"197 ","pages":"Article 104600"},"PeriodicalIF":12.8,"publicationDate":"2025-12-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145844921","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}

{"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 ,&nbsp;Dimitris C. Lagoudas ,&nbsp;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":"2025-12-24","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}

{"title":"U-PolyConformer: Spatiotemporal machine learning for microstructure engineering","authors":"Dylan Budnick ,&nbsp;Benhour Amirian ,&nbsp;Abhijit Brahme ,&nbsp;Haitham El-Kadiri ,&nbsp;Kaan Inal","doi":"10.1016/j.ijplas.2025.104597","DOIUrl":"10.1016/j.ijplas.2025.104597","url":null,"abstract":"<div><div>Accelerating the prediction of mechanical behaviour in heterogenous materials is critical for large-scale microstructure optimization and realizing functionally optimized materials. While existing machine learning approaches have demonstrated an ability to accelerate predictions for the full-field mechanical response of a wide range of heterogenous microstructures, they have been largely limited to monotonic loading conditions. This paper introduces U-PolyConformer, a spatiotemporal machine learning framework that combines U-Net convolutional neural networks with transformer layers, capable of capturing the full-field stress and strain evolution under monotonic and random walk loading conditions. Trained on a large dataset of crystal plasticity finite element method (CPFEM) simulations with FCC polycrystals, the model accurately captures complex phenomena, including strain localization and stress unloading. The U-PolyConformer achieves a 7,900x speed-up over the ground-truth CPFEM simulations while producing high-fidelity results in both interpolative and extrapolative regimes. Comprehensive evaluations demonstrate the U-PolyConformer’s capacity to generalize outside the training distribution to novel microstructures, loading conditions, and strain hardening behaviours. To highlight the model’s potential as a surrogate for accelerating computational materials engineering workflows, a microstructure optimization framework based on static recrystallization is introduced and used to delay the onset of localization. This framework is successfully used to identify the grains which initiate the onset of localization, illustrating how the proposed model and optimization framework may be used for identifying and exploring property-performance relationships.</div></div>","PeriodicalId":340,"journal":{"name":"International Journal of Plasticity","volume":"197 ","pages":"Article 104597"},"PeriodicalIF":12.8,"publicationDate":"2025-12-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145822859","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}

{"title":"A continuum study of the role of coupled electrochemistry and stress on the morphological evolution of Li-anode","authors":"Shabnam Konica,&nbsp;Brian W. Sheldon,&nbsp;Vikas Srivastava","doi":"10.1016/j.ijplas.2025.104594","DOIUrl":"10.1016/j.ijplas.2025.104594","url":null,"abstract":"<div><div>We present a continuum-level electro-chemo-mechanical framework that captures the coupled influence of stress and electrochemistry on the morphological evolution of viscoplastic Li-metal anodes and solid electrolyte interphase (SEI) layers in liquid-electrolyte Li-metal batteries. Our model incorporates a two-way coupling between mechanical deformation and electrochemical transport, including stress-modulated Li-ion migration across the SEI, large deformation viscoplasticity of the Li-anode during plating/stripping cycles, and surface energy effects at the anode interface. This multiphysics approach enables a systematic investigation of how electrochemical (e.g., diffusivity, conductivity), mechanical (e.g., modulus, residual stress), and geometric (e.g., thickness) properties of the SEI affect interfacial stability. Through numerical simulations, we generate design maps that quantify the roles of SEI geometry, material properties, and current density in either suppressing or amplifying surface instabilities. Crucially, our results highlight the dominant role of Li-metal viscoplasticity in driving surface roughening – even under homogeneous SEI conditions – a factor often overlooked in earlier linear stability or decoupled studies. We also explore the performance of composite and bi-layer SEIs, offering insights into optimal combinations of mechanical stiffness and interfacial energy to block protrusion growth. Together, this work offers a predictive modeling tool and design guidance for engineering artificial SEIs to suppress dendrite formation and enable fast, stable cycling of Li-metal batteries.</div></div>","PeriodicalId":340,"journal":{"name":"International Journal of Plasticity","volume":"197 ","pages":"Article 104594"},"PeriodicalIF":12.8,"publicationDate":"2025-12-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145823727","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}

{"title":"Strain rate-driven transition between dislocation slip and twinning in Ti-6Al-4V ELI alloy during tensile deformation","authors":"Mingjie Zhang ,&nbsp;Hui Guo ,&nbsp;Jianke Qiu ,&nbsp;Xiaobing Hu ,&nbsp;Chao Fang ,&nbsp;Hao Wang ,&nbsp;Dongsheng Xu ,&nbsp;Yingjie Ma ,&nbsp;Jiafeng Lei ,&nbsp;Rui Yang","doi":"10.1016/j.ijplas.2025.104599","DOIUrl":"10.1016/j.ijplas.2025.104599","url":null,"abstract":"<div><div>In this work, the strain rate effects on the Ti-6Al-4V ELI alloy under uniaxial tensile loading were systematically investigated over a wide range of strain rates, from quasi-static to dynamic conditions with nominal strain rates ranging from 0.001 to 1000 s^-1. Electron backscatter diffraction technique was used to characterize the evolutions of the mean geometrically necessary dislocation (GND) density and twin boundary fraction with increasing strain rate, while transmission electron microscopy was used to examine changes in dislocation structures. The results reveal the presence of a critical strain rate near 50 s^-1, which divides the strain rate strengthening behavior into two distinct regimes, each characterized by markedly different strain rate sensitivity (SRS) exponents (<span><math><mi>m</mi></math></span>). The contrasting trends in <span><math><mi>m</mi></math></span> value, GND density and twin content indicate a strain rate-induced transition in dominant deformation mechanism—from slip-dominated behavior at lower strain rates to slip-twinning dominated behavior at higher strain rates, which arises from the competitive interplay between dislocation slip and deformation twinning. Additionally, the SRSs of various slip systems and the <span><math><mrow><mrow><mo>{</mo><mrow><mn>10</mn><mover><mn>1</mn><mo>¯</mo></mover><mn>2</mn></mrow><mo>}</mo></mrow><mrow><mo>〈</mo><mrow><mover><mn>1</mn><mo>¯</mo></mover><mn>011</mn></mrow><mo>〉</mo></mrow></mrow></math></span> twinning mode were evaluated through a combination of experimental characterizations and molecular dynamics simulations. Among these, prismatic ⟨<em>a</em>⟩ slip exhibits the highest SRS, explaining its reduced activity under dynamic loading conditions, while twinning, with relatively low SRS, exhibits elevated activity.</div></div>","PeriodicalId":340,"journal":{"name":"International Journal of Plasticity","volume":"197 ","pages":"Article 104599"},"PeriodicalIF":12.8,"publicationDate":"2025-12-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145813011","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}

{"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 ,&nbsp;Yaoyao Wang ,&nbsp;Yanle Li ,&nbsp;Yansen Li ,&nbsp;Guo-jian Lyu ,&nbsp;Heng Chen ,&nbsp;Chenglong Yang ,&nbsp;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 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.</div></div>","PeriodicalId":340,"journal":{"name":"International Journal of Plasticity","volume":"197 ","pages":"Article 104596"},"PeriodicalIF":12.8,"publicationDate":"2025-12-20","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}

{"title":"Potent interplay between L12 nanoprecipitates and 9R phase enabling strength-ductility synergy in a 650 MPa-class additively manufactured aluminum alloy","authors":"Chengzhe Yu ,&nbsp;Xizhen Xia ,&nbsp;Kefu Gan ,&nbsp;Tong Wang ,&nbsp;Peng Dong ,&nbsp;Xiaokang Liang ,&nbsp;Honghui Wu ,&nbsp;Tiechui Yuan ,&nbsp;Ruidi Li","doi":"10.1016/j.ijplas.2025.104595","DOIUrl":"10.1016/j.ijplas.2025.104595","url":null,"abstract":"<div><div>High-strength additively manufactured (AM) Al alloy is critical for advanced lightweight applications, yet conventional strategies relying on large additions of rare-earth (RE) remain costly and sacrifice ductility. Here, we propose an alternative approach for strength-ductility synergy in a laser powder bed fusion-fabricated low-RE Al alloy, via tuning the interplay between L1₂ nano-precipitate and metastable 9R phase. This strategy is simply realized by low-power laser remelting at each building layer, followed by post-print ageing. As evidenced by computational fluid dynamics simulation and microstructural characterization, laser remelting with limited energy input reduces metallurgical defects and residual stress by refining grain microstructures and suppressing turbulent flows during solidification. Simultaneously, it promotes the in-situ formation of 9R domains through driven local Mg/Si segregation and primary L1₂ nanoprecipitates. 9R phases are stabilized when L1₂ nano-precipitates are generated adjacent during post-print ageing, establishing a unique pinning-like stabilization. The 9R domains also impede the growth and coalescence of L1₂-ordered structure. This interplay establishes a feedback mechanism: L1₂ phase inhibits the 9R-phase annihilation, while the 9R structure conversely suppresses L1₂-phase coarsening during aging. According to first-principles calculations: (i) Stacking fault energy is lowered by local Si/Mg segregation, thereby promoting the formation of stacking-faulted 9R phase, even mechanical twins during deformation; (ii) L1₂ nanoparticles thermodynamically stabilize 9R structures by inhibiting the stacking fault annihilation, prolonging their persistence under stress. This coupling mechanism between L1₂ nanoprecipitate and 9R phase enables the present alloy to have an ultrahigh yielding strength over 650 MPa with considerable deformability, predominating most of its previous counterparts.</div></div>","PeriodicalId":340,"journal":{"name":"International Journal of Plasticity","volume":"197 ","pages":"Article 104595"},"PeriodicalIF":12.8,"publicationDate":"2025-12-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145796130","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}

{"title":"A fully coupled multi-physics multi-phase field crystal plasticity finite element model (MPF-CPFEM) for predicting microstructure evolution and thermomechanical behavior in additive manufacturing","authors":"Xinxin Sun ,&nbsp;Lu Wang ,&nbsp;Guochen Peng ,&nbsp;Gengwen Wang ,&nbsp;Yisheng Lu ,&nbsp;Shinji Sakane ,&nbsp;Wentao Yan ,&nbsp;M.W. Fu","doi":"10.1016/j.ijplas.2025.104583","DOIUrl":"10.1016/j.ijplas.2025.104583","url":null,"abstract":"&lt;div&gt;&lt;div&gt;Despite decades of development in high-energy-density (HED) beam additive manufacturing (AM), modeling and simulation of thermomechanical behavior and microstructure evolution have predominantly been performed in pseudo-coupled or one-way coupled modes. This restriction limits its application in multi-track prediction and impedes a comprehensive understanding of the underlying mechanisms in HED beam AM processes. Therefore, this work presents the first two-way, fully coupled, multi-phase field crystal plasticity finite element method (MPF-CPFEM) model, which simultaneously simulates microstructure evolution and thermomechanical behavior during AM processes. The unified MPF model captures recrystallization, grain growth, and liquid–solid transformation, while the CPFEM accounts for polycrystalline deformation, dislocation density evolution, and temperature-dependent thermomechanical response. A mesh-sharing scheme and real-time data exchange enable two-way coupling, supported by a developed element-free Galerkin finite difference method (EFG-FDM) for the accurate calculation of non-local data on deformed meshes, including geometrically necessary dislocations (GNDs) and phase fields. The model incorporates the influence of cellular structure size effects via GND densities derived from the supercooling rate. The validated model is applied to two laser powder bed fusion (LPBF) cases. It replicates morphological characteristics, such as V-shaped grains and the non-uniform surface of the molten pool. Simulations reveal strong two-way coupling between thermomechanical response and heterogeneous deformation. It shows that epitaxially grown regions exhibit different stress and grain orientations from the substrate due to the influence of cellular structures, thermomechanical deformation, and intergranular constraints driven by the molten pool with grain aggregates. The model reveals residual stress accumulation during the dual-track LPBF case and identifies potential crack regions at epitaxial grain boundaries. It captures ultra-rapid dislocation multiplication after limited tracks, which differs from the conventional plastic forming process, cyclic service environment, and solid-state AM processes. Rapid cooling suppresses discontinuous dynamic recrystallization (DDRX), while continuous dynamic recrystallization (CDRX) is found to form after limited laser tracks, driven by extreme deformation at molten pool boundaries in the LPBF process. The application to the dual-track LPBF case demonstrates its inherent capability to tackle the challenge of fully coupling multi-track AM simulations, which is challenging with conventional one-way modeling. As the first endeavor in a fully coupled modeling framework for AM processes, the MPF-CPFEM model offers unique insights into the complex HED beam AM mechanisms. Limitations and prospects, including computational efficiency, potential extension to additional AM processes, computational optimizations, and f","PeriodicalId":340,"journal":{"name":"International Journal of Plasticity","volume":"197 ","pages":"Article 104583"},"PeriodicalIF":12.8,"publicationDate":"2025-12-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145784643","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}