Pub Date : 2025-12-15DOI: 10.1016/j.actamat.2025.121831
Ahmad Mirzaei, Shen J. Dillon
Arrhenius kinetics are central to high-temperature creep but have not routinely produced quantitative, parameter-sparse descriptions of low-temperature plasticity, stress–strain response, or Hall–Petch scaling. We introduce Arrhenius analogues of the Taylor hardening and Hall–Petch models that incorporate two essential microstructural descriptors: a local stress concentration factor ϕ and the volume fraction of rate-limiting interaction sites Ξ. When combined with a minimal dislocation-density evolution law, this “Arrhenius mechanics” framework fits Hall–Petch datasets, true stress–strain curves, and the strain-rate and temperature dependence of strength across materials and microstructures. The formulation also reproduces inverse Hall–Petch behavior and strain softening without ad hoc assumptions. Fitted activation parameters are physically plausible, with H*∼0.1−5eV and v*∼0.1−10b3. Expressing grain boundary-dislocation interactions and dislocation-segment depinning within a common Arrhenius form yields a compact set of scaling relations in stress, grain size, and dislocation spacing that support (i) cross-experiment parameter transfer (e.g., from nanopillar tests to polycrystalline yield), (ii) extrapolation across strain rates and temperatures, and (iii) construction of deformation-mechanism maps using a small number of measurable quantities. The formulation derives from a convex dissipation potential, ensuring thermodynamic consistency. The results suggest accounting for ϕ and Ξ is sufficient to unify plasticity and creep descriptions within a single Arrhenius framework.
{"title":"An Arrhenius Mechanics Model for Polycrystalline Plasticity and Creep","authors":"Ahmad Mirzaei, Shen J. Dillon","doi":"10.1016/j.actamat.2025.121831","DOIUrl":"https://doi.org/10.1016/j.actamat.2025.121831","url":null,"abstract":"Arrhenius kinetics are central to high-temperature creep but have not routinely produced quantitative, parameter-sparse descriptions of low-temperature plasticity, stress–strain response, or Hall–Petch scaling. We introduce Arrhenius analogues of the Taylor hardening and Hall–Petch models that incorporate two essential microstructural descriptors: a local stress concentration factor <mml:math altimg=\"si13.svg\"><mml:mi>ϕ</mml:mi></mml:math> and the volume fraction of rate-limiting interaction sites <mml:math altimg=\"si14.svg\"><mml:mstyle mathvariant=\"normal\"><mml:mi>Ξ</mml:mi></mml:mstyle></mml:math>. When combined with a minimal dislocation-density evolution law, this “Arrhenius mechanics” framework fits Hall–Petch datasets, true stress–strain curves, and the strain-rate and temperature dependence of strength across materials and microstructures. The formulation also reproduces inverse Hall–Petch behavior and strain softening without ad hoc assumptions. Fitted activation parameters are physically plausible, with <mml:math altimg=\"si15.svg\"><mml:mrow><mml:msup><mml:mrow><mml:mi>H</mml:mi></mml:mrow><mml:mo>*</mml:mo></mml:msup><mml:mo>∼</mml:mo><mml:mn>0.1</mml:mn><mml:mo linebreak=\"goodbreak\">−</mml:mo><mml:mn>5</mml:mn><mml:mspace width=\"0.33em\"></mml:mspace><mml:mi>e</mml:mi><mml:mi>V</mml:mi></mml:mrow></mml:math> and <mml:math altimg=\"si16.svg\"><mml:mrow><mml:msup><mml:mrow><mml:mi>v</mml:mi></mml:mrow><mml:mo>*</mml:mo></mml:msup><mml:mo>∼</mml:mo><mml:mn>0.1</mml:mn><mml:mo linebreak=\"goodbreak\">−</mml:mo><mml:mn>10</mml:mn><mml:mspace width=\"0.16em\"></mml:mspace><mml:msup><mml:mrow><mml:mi>b</mml:mi></mml:mrow><mml:mn>3</mml:mn></mml:msup></mml:mrow></mml:math>. Expressing grain boundary-dislocation interactions and dislocation-segment depinning within a common Arrhenius form yields a compact set of scaling relations in stress, grain size, and dislocation spacing that support (i) cross-experiment parameter transfer (e.g., from nanopillar tests to polycrystalline yield), (ii) extrapolation across strain rates and temperatures, and (iii) construction of deformation-mechanism maps using a small number of measurable quantities<ce:bold>.</ce:bold> The formulation derives from a convex dissipation potential, ensuring thermodynamic consistency. The results suggest accounting for <mml:math altimg=\"si13.svg\"><mml:mi>ϕ</mml:mi></mml:math> and <mml:math altimg=\"si14.svg\"><mml:mstyle mathvariant=\"normal\"><mml:mi>Ξ</mml:mi></mml:mstyle></mml:math> is sufficient to unify plasticity and creep descriptions within a single Arrhenius framework.","PeriodicalId":238,"journal":{"name":"Acta Materialia","volume":"117 1","pages":""},"PeriodicalIF":9.4,"publicationDate":"2025-12-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145753322","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}
The longstanding gap between atomistic and mesoscale simulations partly lies in the absence of a direct, physically grounded connection between atomic structure and mesoscale fields. In this work, we present a robust coarse-graining approach to systematically investigate the connection between phase-field and atomistic simulations of grain boundaries (GBs). The atomistic structures of 408 GBs in BCC-Fe and -Mo were studies to compute and analyze a continuous atomic density field. We discover a fundamental relationship between the GB density—defined as the average atomic density at the GB plane—and the GB excess free volume, an integral property of the boundary. An almost perfect linear correlation between the GB atomic density and GB excess free volume is identified. We also show that the width of BCC GBs, when scaled by the lattice constant, approaches a universal constant value. The relationships among GB density, width, and energy are systematically examined for various GB planes, and the GB energy–density correlations are classified with respect to GB types. It turns out that the atomic planes forming the GB strongly influence both the GB density and excess volume. The current results establish a dependable framework to bridge across scales, enabling density-based phase-field modeling of GBs with atomistic fidelity and enhancing the predictive reliability of mesoscale simulations.
{"title":"Linking atomistic and phase-field modelling of grain boundaries I: Coarse-graining atomistic structures","authors":"Theophilus Wallis, Sutach Rattanaphan, Reza Darvishi Kamachali","doi":"10.1016/j.actamat.2025.121786","DOIUrl":"https://doi.org/10.1016/j.actamat.2025.121786","url":null,"abstract":"The longstanding gap between atomistic and mesoscale simulations partly lies in the absence of a direct, physically grounded connection between atomic structure and mesoscale fields. In this work, we present a robust coarse-graining approach to systematically investigate the connection between phase-field and atomistic simulations of grain boundaries (GBs). The atomistic structures of 408 GBs in BCC-Fe and -Mo were studies to compute and analyze a continuous atomic density field. We discover a fundamental relationship between the GB density—defined as the average atomic density at the GB plane—and the GB excess free volume, an integral property of the boundary. An almost perfect linear correlation between the GB atomic density and GB excess free volume is identified. We also show that the width of BCC GBs, when scaled by the lattice constant, approaches a universal constant value. The relationships among GB density, width, and energy are systematically examined for various GB planes, and the GB energy–density correlations are classified with respect to GB types. It turns out that the atomic planes forming the GB strongly influence both the GB density and excess volume. The current results establish a dependable framework to bridge across scales, enabling density-based phase-field modeling of GBs with atomistic fidelity and enhancing the predictive reliability of mesoscale simulations.","PeriodicalId":238,"journal":{"name":"Acta Materialia","volume":"1 1","pages":""},"PeriodicalIF":9.4,"publicationDate":"2025-12-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145753286","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-12-15DOI: 10.1016/j.actamat.2025.121829
Ting Liu, Yunzhu Shi, Liuliu Han, Fei Zhang, Wei Chen, Hongyuan Wan, Chao Ma, Alexander Schökel, Yan Ma, Shaolou Wei, Claudio Pistidda, Zhifeng Lei, Zhaoping Lu
In metals and alloys, solute segregation at grain boundaries typically undermines cohesion and ductility. Here, we overturn this paradigm by showing that solvent Fe atoms can preferentially enrich low-angle grain boundaries (LAGBs) in a ferrous alloy, dramatically enhancing ductility. Cold rolling and aging generate coherent nanoprecipitates, a high dislocation density, and abundant LAGBs in an austenitic matrix, yielding an ultrahigh tensile yield strength of ∼ 1.74 GPa. Moreover, the solvent Fe enrichment at LAGBs lowers local stacking fault energy and activates austenite-to-martensite transformation under load. This transformation-induced plasticity effect stabilizes plastic flow, enabling a uniform elongation of ∼ 26.2% despite the alloy’s exceptional strength. Our findings challenge conventional views of segregation and offer a new design strategy for ultra-strong, highly ductile alloys.
{"title":"Solvent-enriched interface enables ductility in an ultrastrong alloy","authors":"Ting Liu, Yunzhu Shi, Liuliu Han, Fei Zhang, Wei Chen, Hongyuan Wan, Chao Ma, Alexander Schökel, Yan Ma, Shaolou Wei, Claudio Pistidda, Zhifeng Lei, Zhaoping Lu","doi":"10.1016/j.actamat.2025.121829","DOIUrl":"https://doi.org/10.1016/j.actamat.2025.121829","url":null,"abstract":"In metals and alloys, solute segregation at grain boundaries typically undermines cohesion and ductility. Here, we overturn this paradigm by showing that solvent Fe atoms can preferentially enrich low-angle grain boundaries (LAGBs) in a ferrous alloy, dramatically enhancing ductility. Cold rolling and aging generate coherent nanoprecipitates, a high dislocation density, and abundant LAGBs in an austenitic matrix, yielding an ultrahigh tensile yield strength of ∼ 1.74 GPa. Moreover, the solvent Fe enrichment at LAGBs lowers local stacking fault energy and activates austenite-to-martensite transformation under load. This transformation-induced plasticity effect stabilizes plastic flow, enabling a uniform elongation of ∼ 26.2% despite the alloy’s exceptional strength. Our findings challenge conventional views of segregation and offer a new design strategy for ultra-strong, highly ductile alloys.","PeriodicalId":238,"journal":{"name":"Acta Materialia","volume":"51 1","pages":""},"PeriodicalIF":9.4,"publicationDate":"2025-12-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145753278","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-12-12DOI: 10.1016/j.actamat.2025.121827
C. Onofri, X. Iltis, J.P. Monchoux, J. Amodeo, R. Madec, D. Caillard, C. Sabathier, H. Palancher, J. Fouet, D. Drouan, M. Legros
{"title":"Dislocation substructures and networks induced by compression test in polycrystalline UO2 at 1550°C","authors":"C. Onofri, X. Iltis, J.P. Monchoux, J. Amodeo, R. Madec, D. Caillard, C. Sabathier, H. Palancher, J. Fouet, D. Drouan, M. Legros","doi":"10.1016/j.actamat.2025.121827","DOIUrl":"https://doi.org/10.1016/j.actamat.2025.121827","url":null,"abstract":"","PeriodicalId":238,"journal":{"name":"Acta Materialia","volume":"10 1","pages":""},"PeriodicalIF":9.4,"publicationDate":"2025-12-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145730798","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-12-11DOI: 10.1016/j.actamat.2025.121825
Elizabeth Heon, Matthew F. Chisholm, Gerd Duscher
High angle grain boundary structures are typically described by either the Coincidence Site Lattice (CSL) or the Structural Unit (SU) model. Both systems work well for describing high-symmetry periodic structures but are ill-suited to describe the full space of possible grain boundary structures. This is of particular importance given that most boundaries in real materials are non-periodic mixed boundaries. In this work we describe an alternative system of grain boundary structural description, based on interstitial polyhedra, which we term the defect polyhedral system. While other workers have used such polyhedra, ours is the first work to connect the defect polyhedral content of a boundary to the underlying misorientation. Specifically, we argue that defect polyhedra are associated with dislocations, even for high angle boundaries, and that a dislocation model is thus suitable across the entire misorientation range for the tilt boundaries modelled in this work.
{"title":"Using Bernal holes to characterize the experimentally observed grain boundaries of aluminum – An alternative to the structural unit model","authors":"Elizabeth Heon, Matthew F. Chisholm, Gerd Duscher","doi":"10.1016/j.actamat.2025.121825","DOIUrl":"10.1016/j.actamat.2025.121825","url":null,"abstract":"<div><div>High angle grain boundary structures are typically described by either the Coincidence Site Lattice (CSL) or the Structural Unit (SU) model. Both systems work well for describing high-symmetry periodic structures but are ill-suited to describe the full space of possible grain boundary structures. This is of particular importance given that most boundaries in real materials are non-periodic mixed boundaries. In this work we describe an alternative system of grain boundary structural description, based on interstitial polyhedra, which we term the defect polyhedral system. While other workers have used such polyhedra, ours is the first work to connect the defect polyhedral content of a boundary to the underlying misorientation. Specifically, we argue that defect polyhedra are associated with dislocations, even for high angle boundaries, and that a dislocation model is thus suitable across the entire misorientation range for the tilt boundaries modelled in this work.</div></div>","PeriodicalId":238,"journal":{"name":"Acta Materialia","volume":"305 ","pages":"Article 121825"},"PeriodicalIF":9.3,"publicationDate":"2025-12-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145753082","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-12-11DOI: 10.1016/j.actamat.2025.121816
Xin Xu, Yan Chen, Boyuan Gou, Turab Lookman, Upadrasta Ramamurty, Jun Sun, Xiangdong Ding
In-situ X-ray computed tomography (XCT) is often used to explore failure mechanisms of materials through the global information of all the detected defects or the typical ones. However, the methodologies proposed hitherto often fall short in capturing the evolution of individual defects and their spatiotemporal characteristics. Herein, we develop a method for tracking each individual defect from its initial state to the point of fracture, with the objective of studying the defect’s evolution as a function of the tensile strain. Our tracking approach represents defects as 3D point clouds and evaluates their morphological similarity with an emphasis on their local environmental similarity. This significantly improves the average tracking accuracy, compared to the existing methods. We further reconstruct the fracture topology tree using the tracking outcomes so that the original critical defect that leads to the ultimate fracture can be identified. Using this methodology, we analyze the spatiotemporal evolution of pores in 316L austenitic stainless steel fabricated using the laser powder bed fusion technique. The results reveal that the combination of morphology parameter (Mdefect) and environmental interaction parameter (Fenv) are efficient and simple tools to capture the evolving characteristics of defects during tension. They enable the accurate identification of the critical defect that leads to fracture, once the tensile strain is sufficient such that the undetected defects/imperfect boundaries become visible to XCT. Using them, a simple unsupervised learning method, which enables a reasonable prediction of the fracture-related defects at a given strain, is also proposed.
{"title":"Spatiotemporal Evolution of Defects in an Additively Manufactured Alloy Monitored through in-situ X-ray Computed Tomography","authors":"Xin Xu, Yan Chen, Boyuan Gou, Turab Lookman, Upadrasta Ramamurty, Jun Sun, Xiangdong Ding","doi":"10.1016/j.actamat.2025.121816","DOIUrl":"https://doi.org/10.1016/j.actamat.2025.121816","url":null,"abstract":"<em>In-situ</em> X-ray computed tomography (XCT) is often used to explore failure mechanisms of materials through the global information of all the detected defects or the typical ones. However, the methodologies proposed hitherto often fall short in capturing the evolution of individual defects and their spatiotemporal characteristics. Herein, we develop a method for tracking each individual defect from its initial state to the point of fracture, with the objective of studying the defect’s evolution as a function of the tensile strain. Our tracking approach represents defects as 3D point clouds and evaluates their morphological similarity with an emphasis on their local environmental similarity. This significantly improves the average tracking accuracy, compared to the existing methods. We further reconstruct the fracture topology tree using the tracking outcomes so that the original critical defect that leads to the ultimate fracture can be identified. Using this methodology, we analyze the spatiotemporal evolution of pores in 316L austenitic stainless steel fabricated using the laser powder bed fusion technique. The results reveal that the combination of morphology parameter (<em>M<sub>defect</sub></em>) and environmental interaction parameter (<em>F<sub>env</sub></em>) are efficient and simple tools to capture the evolving characteristics of defects during tension. They enable the accurate identification of the critical defect that leads to fracture, once the tensile strain is sufficient such that the undetected defects/imperfect boundaries become visible to XCT. Using them, a simple unsupervised learning method, which enables a reasonable prediction of the fracture-related defects at a given strain, is also proposed.","PeriodicalId":238,"journal":{"name":"Acta Materialia","volume":"8 1","pages":""},"PeriodicalIF":9.4,"publicationDate":"2025-12-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145717811","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}
The ferroelastic domain structure is a key factor in controlling the physical properties of multiferroic BiFeO3 (BFO). Despite its sensitivity to strain/stress, mechanical manipulation of the ferroelastic domain structure in BFO remains a challenge in practice, limiting the potential of domain engineering of the functionalities of BFO. Based on scanning probe microscopy experiments and phase-field simulations, we show that nanoindentation is effective to trigger and control stripe-to-monodomain switching of the 71° ferroelastic domain structure in BFO thin films. A windmill-like monodomain pattern is found to be stabilized in the film after nanoindentation, with the size of the pattern dependent on the loading force but its shape almost unaffected by indenter orientation. Moreover, the switching is accompanied by significant changes of the global and local photovoltaic responses of the BFO films, with an ON/OFF ratio of the photovoltaic currents reaching over an order of magnitude. An interesting grid-like hierarchical domain pattern with “isolate islands” of high photoconductivity can be fabricated by nanoindentation arrays. Our results therefore demonstrate the mechanical processability of the domain structure and physical property of BFO thin films and nanoindentation as a potential processing technique for fabrication of micro/nano devices based on ferroic domains.
{"title":"Photovoltaic Switches with Mechanical Knobs: Reconfigurable Ferroelastic Domain Engineering in BiFeO3 Thin Films via Nanoindentation","authors":"Mengjun Wu, Xintong Wang, Qian He, Jianhua Ren, Fei Sun, Yue Zheng, Weijin Chen","doi":"10.1016/j.actamat.2025.121826","DOIUrl":"https://doi.org/10.1016/j.actamat.2025.121826","url":null,"abstract":"The ferroelastic domain structure is a key factor in controlling the physical properties of multiferroic BiFeO<sub>3</sub> (BFO). Despite its sensitivity to strain/stress, mechanical manipulation of the ferroelastic domain structure in BFO remains a challenge in practice, limiting the potential of domain engineering of the functionalities of BFO. Based on scanning probe microscopy experiments and phase-field simulations, we show that nanoindentation is effective to trigger and control stripe-to-monodomain switching of the 71° ferroelastic domain structure in BFO thin films. A windmill-like monodomain pattern is found to be stabilized in the film after nanoindentation, with the size of the pattern dependent on the loading force but its shape almost unaffected by indenter orientation. Moreover, the switching is accompanied by significant changes of the global and local photovoltaic responses of the BFO films, with an ON/OFF ratio of the photovoltaic currents reaching over an order of magnitude. An interesting grid-like hierarchical domain pattern with “isolate islands” of high photoconductivity can be fabricated by nanoindentation arrays. Our results therefore demonstrate the mechanical processability of the domain structure and physical property of BFO thin films and nanoindentation as a potential processing technique for fabrication of micro/nano devices based on ferroic domains.","PeriodicalId":238,"journal":{"name":"Acta Materialia","volume":"1 1","pages":""},"PeriodicalIF":9.4,"publicationDate":"2025-12-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145717812","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-12-10DOI: 10.1016/j.actamat.2025.121822
Xier Luo , Jinxiong Hou , Tzuhsiu Chou , Jie Gan , Jianyang Zhang , Jiang Ju , Bo Xiao , Weicheng Xiao , Yinghao Zhou , Boxuan Cao , Tao Yang
Alloys strengthened by the D019 intermetallic phases exhibit considerable promise for high-temperature applications. However, they generally suffer from the inherent brittleness, which seriously limits their widespread use. In this work, we elaborately designed a novel D019-strengthened high-entropy alloy (HEA) featuring the directional lamellar and granular structured (DLGS) precipitation behavior. This new-type DLGS alloy exhibits substantially enhanced strength-ductility synergy over a wide temperature range from room temperature to 900°C in comparison to the conventional non-directional lamellar structured (NDLS) counterpart. Specifically, the DLGS alloy maintains high yield strength of 821, 770, and 670 MPa at room temperature, 700, and 800°C, respectively. More prominently, the ductilities exceed 25 % at all these temperatures, indicating the elimination of the intermediate-temperature embrittlement, which is evident in the NDLS alloys. Systematic microstructural characterizations reveal that temperature-dependent deformation mechanisms are highly correlated with stacking faults (SFs) and deformation twins (DTs) activated at different temperatures. Furthermore, the origins of initiating SFs and DTs in the DLGS alloy are discussed in detail. The introduction of unshearable D019 precipitates leads to local stress accumulation at the interface, which further contributes to the formation of SFs and DTs. Meanwhile, these precipitates can also impede boundary mobility and suppress grain growth through the Zener drag effect, thereby increasing the starting temperatures of dynamic recrystallization. This work would offer valuable guidance for designing advanced precipitate-strengthened HEAs with superior mechanical performance toward wide-temperature structural applications.
{"title":"Enhanced strength-ductility combinations over a wide temperature range in high-entropy alloys via manipulating the nano-lamellar precipitation behavior","authors":"Xier Luo , Jinxiong Hou , Tzuhsiu Chou , Jie Gan , Jianyang Zhang , Jiang Ju , Bo Xiao , Weicheng Xiao , Yinghao Zhou , Boxuan Cao , Tao Yang","doi":"10.1016/j.actamat.2025.121822","DOIUrl":"10.1016/j.actamat.2025.121822","url":null,"abstract":"<div><div>Alloys strengthened by the D0<sub>19</sub> intermetallic phases exhibit considerable promise for high-temperature applications. However, they generally suffer from the inherent brittleness, which seriously limits their widespread use. In this work, we elaborately designed a novel D0<sub>19</sub>-strengthened high-entropy alloy (HEA) featuring the directional lamellar and granular structured (DLGS) precipitation behavior. This new-type DLGS alloy exhibits substantially enhanced strength-ductility synergy over a wide temperature range from room temperature to 900°C in comparison to the conventional non-directional lamellar structured (NDLS) counterpart. Specifically, the DLGS alloy maintains high yield strength of 821, 770, and 670 MPa at room temperature, 700, and 800°C, respectively. More prominently, the ductilities exceed 25 % at all these temperatures, indicating the elimination of the intermediate-temperature embrittlement, which is evident in the NDLS alloys. Systematic microstructural characterizations reveal that temperature-dependent deformation mechanisms are highly correlated with stacking faults (SFs) and deformation twins (DTs) activated at different temperatures. Furthermore, the origins of initiating SFs and DTs in the DLGS alloy are discussed in detail. The introduction of unshearable D0<sub>19</sub> precipitates leads to local stress accumulation at the interface, which further contributes to the formation of SFs and DTs. Meanwhile, these precipitates can also impede boundary mobility and suppress grain growth through the Zener drag effect, thereby increasing the starting temperatures of dynamic recrystallization. This work would offer valuable guidance for designing advanced precipitate-strengthened HEAs with superior mechanical performance toward wide-temperature structural applications.</div></div>","PeriodicalId":238,"journal":{"name":"Acta Materialia","volume":"304 ","pages":"Article 121822"},"PeriodicalIF":9.3,"publicationDate":"2025-12-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145711539","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}
京公网安备 11010802042870号
京ICP备2023020795号-1
扫码关注我们
求助内容：
应助结果提醒方式：