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":"2026-02-01","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":"A physics-based microscale model for predicting Coble creep deformation: Incorporating stress–diffusion interactions and effects of polycrystalline morphology","authors":"Kota Sagara ,&nbsp;Mitsuhiro Ito ,&nbsp;Takayuki Kitamura ,&nbsp;Kazuki Shibanuma","doi":"10.1016/j.ijplas.2026.104609","DOIUrl":"10.1016/j.ijplas.2026.104609","url":null,"abstract":"<div><div>Accurate evaluation of material creep behaviour is essential for the reliable operation of industrial equipment. In this study, we propose a physics-based model capable of quantitatively predicting the deformation of three-dimensional polycrystalline solids due to Coble creep. The proposed model avoids non-physical assumptions commonly adopted in conventional numerical analyses and reproduces stress-induced grain boundary diffusion—the fundamental mechanism underlying Coble creep—in a physically consistent manner. This is achieved by explicitly representing the three-dimensional grain boundary network and accounting for the interaction between stress and atomic diffusion along grain boundaries. To validate the proposed model, its numerical simulation results were compared with the theoretical equation for Coble creep deformation under uniaxial loading and with the established knowledge under multiaxial loading. The model accurately reproduces the dependence of the macroscopic creep strain rate on grain size, applied stress, and temperature, consistent with the theoretical equation. Furthermore, systematic numerical simulations were conducted to investigate the effects of polycrystalline morphology, such as grain size distribution and aspect ratio, on Coble creep deformation. The results demonstrate that variations in grain size distribution and grain aspect ratio in polycrystalline morphology can lead to measurable changes in the macroscopic creep response, even under identical loading and temperature conditions. The proposed model provides a physically grounded tool for predicting Coble creep deformation of materials under arbitrary loading conditions and polycrystalline morphologies. Moreover, it elucidates the role of microstructural factors in determining material performance, thereby advancing the understanding of GB diffusion-controlled deformation mechanisms at low stresses and over extended timescales.</div></div>","PeriodicalId":340,"journal":{"name":"International Journal of Plasticity","volume":"197 ","pages":"Article 104609"},"PeriodicalIF":12.8,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145956519","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":"Strong, ductile, and hierarchical multiscale heterostructured magnesium alloy via coarse-grained twins coupled with fine-grained precipitates","authors":"Shuaishuai Liu ,&nbsp;Liuyong He ,&nbsp;Tianjiao Li ,&nbsp;Liping Zhong ,&nbsp;Mingshuai Huo ,&nbsp;Yongjian Wang ,&nbsp;Wenzhen Xia ,&nbsp;Wenhuan Chen ,&nbsp;Wenbin Zhang ,&nbsp;Qiyang He ,&nbsp;Manoj Gupta ,&nbsp;Guangsheng Huang ,&nbsp;Bin Jiang ,&nbsp;Fusheng Pan","doi":"10.1016/j.ijplas.2026.104608","DOIUrl":"10.1016/j.ijplas.2026.104608","url":null,"abstract":"<div><div>Heterostructured materials provide a promising path to address the strength-ductility trade-off in Mg alloys. However, designs relying solely on grain size heterogeneity often yield limited improvements. Herein, we fabricated multiscale heterostructures in an AZ91 alloy, featuring twin-modified coarse grains and precipitate-hardened fine grains, through a combination of pre-aging, extrusion, and pre-compression treatments. The obtained material exhibits an exceptional strength-ductility combination, outperforming most existing AZ91 alloys. Mechanistic investigations reveal that this favorable combination is primarily driven by enhanced hetero-deformation induced (HDI) strengthening and hardening, which result from the accumulation of geometrically necessary dislocations (GNDs) at multiscale interfaces. Additional contributions arise from twin-matrix interactions that activate non-basal slip systems, as well as a composite strengthening effects induced by precipitates, dislocation cells, and stacking faults. The multiscale heterostructures promote uniform deformation through slip transfer, stress redistribution, and strain delocalization. Strain hardening is initially dominated by HDI effects, while traditional dislocation-mediated mechanisms become predominant at larger strain. The present approach, integrating precipitate engineering, grain size control, and crystallographic design, provides general guidelines for developing advanced lightweight materials.</div></div>","PeriodicalId":340,"journal":{"name":"International Journal of Plasticity","volume":"197 ","pages":"Article 104608"},"PeriodicalIF":12.8,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145903361","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":"2026-02-01","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":"Cross-slip and easy-glide CRSS in titanium: Theoretical predictions and in-situ TEM measurements","authors":"Tolga Berkay Celebi ,&nbsp;Orcun Koray Celebi ,&nbsp;Daegun You ,&nbsp;Ahmed Sameer Khan Mohammed ,&nbsp;Ashley Bucsek ,&nbsp;Huseyin Sehitoglu","doi":"10.1016/j.ijplas.2025.104605","DOIUrl":"10.1016/j.ijplas.2025.104605","url":null,"abstract":"<div><div>This study investigates the mechanics of prismatic and first-order pyramidal <span><math><mrow><mo>〈</mo><mi>a</mi><mo>〉</mo></mrow></math></span> slip in titanium (Ti), elucidating the physics of easy-glide and cross-slip through a combination of theory and experiments. Screw-character prismatic (Pr) dislocations in Ti are of particular interest because their complex cores can be stable or unstable, leading to activation by either cross-slip or planar glide. To investigate these mechanisms, site-specific micro tensile samples were prepared using focused ion beam (FIB) milling and mounted on a push-to-pull (PTP) device for in-situ transmission electron microscopy (TEM) tensile testing. The in-situ experiments provide direct observations of the onset of dislocation motion and the precise determination of the critical resolved shear stress (CRSS) for the activated mechanisms, and its evolution with load cycling. A comprehensive theory has been developed to predict the CRSS values for easy glide, cross-slip, and multiplication of dislocations. Predicted critical stresses for pyramidal (π)-to-Pr and reverse cross-slip agree closely with the experimental measurements. The latter cross-slip stress is a factor of two higher than that of unobstructed planar slip. The model accounts for overlapping dislocation cores and employs a Wigner-Seitz based cell to evaluate misfit energies. By combining ab initio density functional theory (DFT) with anisotropic elasticity, the framework identifies minimum energy pathways for dislocation glide, which can be intermittent and zig-zag. A simplified expression utilizing (π) and Pr Schmid factor ratios is proposed for critical stress corresponding to (π)-to-Pr cross-slip transition. The results are strongly dependent on crystal orientation, underscoring non-Schmid behavior. Overall, this study explores key critical stress parameters essential for informing higher-scale simulations of plasticity in Ti.</div></div>","PeriodicalId":340,"journal":{"name":"International Journal of Plasticity","volume":"197 ","pages":"Article 104605"},"PeriodicalIF":12.8,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145894272","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":"An interface-regularized phase field model for deformation twinning","authors":"Linfeng Jiang ,&nbsp;Guisen Liu ,&nbsp;Peipeng Jin ,&nbsp;Yao Shen ,&nbsp;Jian Wang","doi":"10.1016/j.ijplas.2025.104569","DOIUrl":"10.1016/j.ijplas.2025.104569","url":null,"abstract":"<div><div>Deformation twinning, a common deformation mechanism in metals with a hexagonal close-packed (HCP) structure, produces plastic strain accompanied with the creation of twinned domains within the matrix. Phase-field models for deformation twinning often suffer from unphysically diffuse or overly wide interfaces, particularly under large and inhomogeneous driving forces. Maintaining a dynamically stable interface is essential for achieving an accurate description of interface motion. In this work, we propose a Forward-Backward Regularization (FBR) method to control the width of twin interfaces. This is accomplished by introducing an energy penalty term—linked to the gradient magnitude of the order parameter—into the total free energy functional. This method decouples the numerical control of interface width from the physical material parameters (e.g., interfacial energy), thereby preserving their intrinsic physical significance. The FBR method demonstrates robust performance in multiple scenarios, including interfacial energy-driven interface contraction, bulk driving force-induced interface expansion, and mesh size insensitivity to twin propagation. Integrated the FBR model into a coupled Crystal Plasticity Finite Element - Phase Field (CPFE-PF) model, the FBR approach is examined to effectively control interface width, reduce mesh orientation sensitivity, and reproduce twin propagation and transmission across grain boundaries. This robust, computationally efficient FBR model holds promise for broader applications in PF modeling of shear transformation bands with precise interface control.</div></div>","PeriodicalId":340,"journal":{"name":"International Journal of Plasticity","volume":"196 ","pages":"Article 104569"},"PeriodicalIF":12.8,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145600093","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 new strategy for fabricating Mg-Al alloys with excellent strength-ductility synergy via pulse-coupled wire-arc directed energy deposition","authors":"Yukang An ,&nbsp;Enyu Guo ,&nbsp;Diyang Xia ,&nbsp;Shuo Yin ,&nbsp;Zhirou Zhang ,&nbsp;Wuyue Zheng ,&nbsp;Zongning Chen ,&nbsp;Huijun Kang ,&nbsp;Tongmin Wang","doi":"10.1016/j.ijplas.2025.104550","DOIUrl":"10.1016/j.ijplas.2025.104550","url":null,"abstract":"<div><div>Wire-arc directed energy deposition (W-DED) is a cost-effective additive manufacturing technology increasingly applied to the fabrication of magnesium alloy components. However, AZ-series magnesium alloys fabricated by conventional DED suffer from inadequate properties and premature failure due to stress concentration caused by coarse structure and high fraction of porosity. In this work, a high-energy pulsed arc is introduced into the W-DED of AZ31B alloy, and its effects on porosity, microstructure, mechanical properties, and deformation damage behavior are comprehensively investigated. The pulsed-coupled DED (CMT+P) process significantly enhances component densification while refining grains and precipitates by intensifying solidification dynamics and modifying solute redistribution. The AZ31B alloy fabricated by CMT+P process exhibits a superior strength-ductility synergy, with ultimate tensile strength of 262 ± 1.5 MPa along BD and 267 ± 2 MPa along TD accompanied by a total elongation of 24.7 ± 1.8 % and 25.4 ± 1.5 %, respectively. <em>In-situ</em> synchrotron tomography from a novel “primary damage band (PDB)” perspective reveals the competitive relationship between initial and derived pores of deformation behavior. During the progressive damage evolution, the optimized structure crucially suppresses derived pore nucleation and delays stress accumulation to enhance damage tolerance and promote uniform plastic deformation. This work provides a new strategy for fabricating high-performance Mg-Al DED components that combine high performance with superior damage resistance.</div></div>","PeriodicalId":340,"journal":{"name":"International Journal of Plasticity","volume":"196 ","pages":"Article 104550"},"PeriodicalIF":12.8,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145509404","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 generalized variational framework for crack regularization: Mixed-mode fracture and crack propagation direction","authors":"Liang Xue ,&nbsp;Jian-Ying Wu","doi":"10.1016/j.ijplas.2025.104573","DOIUrl":"10.1016/j.ijplas.2025.104573","url":null,"abstract":"<div><div>This study proposes a generalized variational framework for mixed-mode crack regularization. It addresses two critical challenges of existing phase-field models, i.e., mis-predictions of mode-dependent fracture energy and of the crack propagation direction. For the former, a cohesive phase-field model with <em>one single field variable</em> and <em>two distinct fracture energies</em> is established for mixed-mode failure. Regarding the <em>a priori</em> unknown crack direction indispensable for the orthogonal energy decomposition, the criterion of minimum potential energy is derived within the generalized variational framework. Rational and robust crack paths can be predicted across a large range of material parameters and loading scenarios. Abrupt jumps in the crack direction and the resulting numerical instabilities exhibited by the criterion of maximum crack driving force are eliminated. Finally, the proposed variational framework is verified by a series of benchmark numerical examples involving complex crack propagation.</div></div>","PeriodicalId":340,"journal":{"name":"International Journal of Plasticity","volume":"196 ","pages":"Article 104573"},"PeriodicalIF":12.8,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145657431","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":"Anisotropic compression behavior of 316 L stainless steel at room and cryogenic temperatures: The influence of twinning and transformation mechanisms","authors":"Saurabh Pawar ,&nbsp;K.U. Yazar ,&nbsp;Khushahal Thool ,&nbsp;Wi-Geol Seo ,&nbsp;Chang-Gon Jeong ,&nbsp;Yoon-Uk Heo ,&nbsp;Shi-Hoon Choi","doi":"10.1016/j.ijplas.2025.104572","DOIUrl":"10.1016/j.ijplas.2025.104572","url":null,"abstract":"<div><div>This study investigates the microstructural evolution and deformation behavior of 316 L stainless steel (SS) fabricated by direct energy deposition under compressive loading at room temperature (RT) and cryogenic temperature (CT), along the scanning (SD) and transverse (TD) directions. Electron backscatter diffraction, transmission electron microscopy, and electron channeling contrast imaging, combined with dislocation-based crystal plasticity simulations, were employed. The as-fabricated microstructure exhibited columnar grains with cellular substructures, and δ-ferrite at cell boundaries enriched in Cr and Mo. At RT, SD samples deformed via dislocation glide and twinning in [001]-oriented grains, gradually reorienting toward the less favorable [110] direction. TD samples predominantly deformed by slip. At CT, yield strength differed significantly between SD and TD samples, indicating mechanical anisotropy arising from grain morphology, local stress heterogeneities, and martensitic transformations (γ → ε → α′ and γ → α′). Simulations incorporating twinning- and transformation-induced plasticity (TWIP and TRIP) showed that [110]- and [111]-oriented grains relative to the loading direction exhibited higher resistance to deformation, consistent with lower twinning and martensite formation. At RT, twinning and screw dislocation glide were dominant, while at CT, anisotropy was governed by the interaction between hard and soft phases, with martensite variant selection playing a central role. The activation of TWIP and TRIP was strongly dependent on crystallographic orientation, with [001]-oriented grains showing greater deformation tendency.</div></div>","PeriodicalId":340,"journal":{"name":"International Journal of Plasticity","volume":"196 ","pages":"Article 104572"},"PeriodicalIF":12.8,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145619620","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":"Tailoring dislocation structure and constructing coherent Y2Ti2O7 and Laves stacking faults in 9Cr ODS alloys: A multiple strategy to enhance the strength and ductility","authors":"Mingsheng Yang,&nbsp;Jikang Li,&nbsp;Shengjie Dong,&nbsp;Zhichen Wang,&nbsp;Tong Liu","doi":"10.1016/j.ijplas.2025.104577","DOIUrl":"10.1016/j.ijplas.2025.104577","url":null,"abstract":"<div><div>Simultaneously enhancing strength and ductility poses a significant challenge in 9Cr oxide dispersion strengthened (ODS) ferritic-martensitic (F-M) alloys. In this work, we propose a novel strategy combining Al-Si co-alloying with direct addition of Y₂Ti₂O₇ nanoparticles (YTO NPs), and then employing one-step quenching without tempering heat treatment to simultaneously tailor dislocation structure and construct coherent YTO NPs as well as Laves phase stacking faults (SFs) in 9Cr ODS F-M alloys. Our study reveals that adjusting Al/Si content can optimize martensite volume fraction and aspect ratio, and YTO NPs can suppress dislocation nucleation within the martensitic plane through coherent interface. This synergy mechanism improves strength-ductility via optimizing dislocation density. During deformation, besides the conventional YTO-dislocation mechanism, YTO NPs can simultaneously pin dislocations in different slip systems. Remarkably, YTO NPs can also induce the dual formation of dislocation loops and dipoles, which will inhibit the formation of axial cracks. Moreover, the precipitation of ∼100 nm Laves phases in matrix (BCC) creates deformable zones that evolve into Laves SFs, ultimately improving strength-ductility synergy. 1.5Al1Si alloy (1.5 wt% Al and 1 wt% Si) aligns with the Kocks-Mecking model, where YTO NPs and Laves SFs simultaneously enhance dislocation storage capacity (θ₀) while Laves SFs suppressing dynamic recovery (K), consequently improving work hardening rate. Finally, 1.5Al1Si alloy exhibits up to 1.2 GPa ultimate tensile strength (<em>R</em>_m) while maintaining 8.4 % of total extension at maximum force (<em>A</em>_gt). This study proposes a new strategy to enhance the strength and ductility of ODS alloys.</div></div>","PeriodicalId":340,"journal":{"name":"International Journal of Plasticity","volume":"196 ","pages":"Article 104577"},"PeriodicalIF":12.8,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145689268","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}