Acta Materialia最新文献_第3页

Synthetic training data for CT image segmentation of microstructures 显微结构CT图像分割的合成训练数据

IF 9.4 1区材料科学

Acta Materialia Pub Date : 2025-06-18 DOI: 10.1016/j.actamat.2025.121220

Lars Griem, Arnd Koeppe, Alexander Greß, Thomas Feser, Britta Nestler

引用次数: 0

Combining structural and chemical heterogeneities on the nanoscale to enable ductile solid solution with record-high specific strength

IF 9.4 1区材料科学

Acta Materialia Pub Date : 2025-06-18 DOI: 10.1016/j.actamat.2025.121270

Qinghui Tang, Xingwang Cheng, Fan Zhang, Shipan Yin, Jingyao He, Zigao Zhang, Fei Zhang, Qingjin Zeng, Zezhou. Li, Hongmei Zhang, Junping Li, Evan Ma

{"title":"Combining structural and chemical heterogeneities on the nanoscale to enable ductile solid solution with record-high specific strength","authors":"Qinghui Tang, Xingwang Cheng, Fan Zhang, Shipan Yin, Jingyao He, Zigao Zhang, Fei Zhang, Qingjin Zeng, Zezhou. Li, Hongmei Zhang, Junping Li, Evan Ma","doi":"10.1016/j.actamat.2025.121270","DOIUrl":"https://doi.org/10.1016/j.actamat.2025.121270","url":null,"abstract":"Heterogeneous nanostructuring can strengthen metallic materials without excessive degradation in strain hardening and ductility. Here we show that the complex concentrated make-up in multi-principal element alloys makes it feasible to combine structural and chemical heterogeneities together, both at high levels and on the nanoscale, as demonstrated in a lightweight (Ti<sub>55</sub>V<sub>30</sub>Zr<sub>15</sub>)<sub>95</sub>Al<sub>5</sub> alloy (∼ 5.16 g/cm<sup>3</sup>). First, the pronounced local chemical ordering (LCO) promotes “dislocation channels” upon room-temperature rolling. This micro-deformation localization induces numerous nano-deformation bands, many of which are refined into nanocrystalline grains during extended cold rolling. Second, subsequent ageing leads to spinodal decomposition, thereby introducing compositional undulations on the nanoscale. Combined structural and chemical heterogeneities promote strengthening and strain hardening, leading to a record-high yield strength (∼ 1.7 GPa) and specific yield strength (326 MPa·cm<sup>3</sup>·g<sup>-1</sup>), while retaining a respectable elongation-to-failure over 10%, a combination unprecedented in previous lightweight alloys. Our success showcases a novel heterogeneity strategy that achieves unusually high strength without hard precipitates, opening a solid solution route towards high-performance lightweight alloys.","PeriodicalId":238,"journal":{"name":"Acta Materialia","volume":"180 1","pages":""},"PeriodicalIF":9.4,"publicationDate":"2025-06-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144319355","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}

引用次数: 0

Direct microstructural observations and atomistic simulations on Hematite to Magnetite reduction 赤铁矿还原成磁铁矿的直接微观结构观察与原子模拟

IF 8.3 1区材料科学

Acta Materialia Pub Date : 2025-06-18 DOI: 10.1016/j.actamat.2025.121269

V. Chavan , N.N. Pai , A. Prakash , P. Raut , B. Hazra , H.K. Mehtani , H. Sharma , S. Girish , S. Nag , S. Kundu , S. Basu , A. Alam , A.S. Panwar , I. Samajdar

{"title":"Direct microstructural observations and atomistic simulations on Hematite to Magnetite reduction","authors":"V. Chavan , N.N. Pai , A. Prakash , P. Raut , B. Hazra , H.K. Mehtani , H. Sharma , S. Girish , S. Nag , S. Kundu , S. Basu , A. Alam , A.S. Panwar , I. Samajdar","doi":"10.1016/j.actamat.2025.121269","DOIUrl":"10.1016/j.actamat.2025.121269","url":null,"abstract":"<div><div>This study used a combination of direct microstructural observations and atomistic simulations to examine Hematite to Magnetite reduction under molecular hydrogen. Reduction at 1123 K revealed noticeable microscopic strains, and associated grain fragmentation with increased defect densities plus residual stresses. Larger Magnetite grains exhibited deformation twinning, which reduced the transformation induced elastic-plastic deformation. Experimental orientation relationship (∼<span><math><mrow><msup><mrow><mn>50</mn></mrow><mo>∘</mo></msup><mo><</mo><mn>110</mn><mo>></mo></mrow></math></span>) and lattice correspondence-based transformation strains were also established. Atomistic simulations involved both reactive force field molecular dynamics (ReaxFF MD) and density functional theory (DFT). None of the ReaxFF parametrizations were able to fully capture all the thermodynamic and physical properties of the oxide phases. Choice of a specific parametrization was based on its ability to model the transition from α-Hematite to γ-Hematite or Maghemite. This was also shown with subsequent DFT calculations and direct microstructural observations. Experimentally, two distinct transformation paths emerged: (I) direct Hematite-to-Magnetite reduction and (II) Hematite-to-Magnetite transformation through Maghemite. Though (I) and (II) were crystallographically identical, (II) was observed <span><math><mrow><mo>≥</mo><mo>∼</mo><mn>973</mn><mi>K</mi></mrow></math></span> and had significantly more microscopic strains. Maghemite transition, and corresponding atomic shear, emerged as a key factor for transformation-induced microscopic strains, which is critical to the overall reduction kinetics. ReaxFF MD simulated this atomistic shear of experimental Maghemite formation.</div></div>","PeriodicalId":238,"journal":{"name":"Acta Materialia","volume":"296 ","pages":"Article 121269"},"PeriodicalIF":8.3,"publicationDate":"2025-06-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144311677","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}

引用次数: 0

Depth-dependent microstructural observations reveal the role of thermal cycling on the formation of a hierarchical dislocation cell structure during selective laser melting of 316L stainless steel

IF 9.4 1区材料科学

Acta Materialia Pub Date : 2025-06-18 DOI: 10.1016/j.actamat.2025.121271

Jinming Fan, Weiyi Wang, Yueyue Zhu, Andrew Godfrey, Hanqing Che, Xiaoxu Huang

{"title":"Depth-dependent microstructural observations reveal the role of thermal cycling on the formation of a hierarchical dislocation cell structure during selective laser melting of 316L stainless steel","authors":"Jinming Fan, Weiyi Wang, Yueyue Zhu, Andrew Godfrey, Hanqing Che, Xiaoxu Huang","doi":"10.1016/j.actamat.2025.121271","DOIUrl":"https://doi.org/10.1016/j.actamat.2025.121271","url":null,"abstract":"Detailed microstructural observations as a function of depth from the surface of the final melt pool using both transmission electron microscopy (TEM) and electron back-scatter diffraction (EBSD) have been carried out. The observations show that a well-defined dislocation cell block structure is formed during selective laser melting (SLM) of 316L stainless steel, resulting in hierarchical dislocation cell structure in interior volumes. Specifically, orientation measurements using both TEM and EBSD, combined with high-angle annular dark-field imaging, show that the evolution of the dislocation cell-block structure in SLM-prepared 316L is a combined effect of deformation, solute segregation, and thermal cycling. A segregation network forms first during solidification and then stresses due to rapid solidification/cooling coupled with melt-pool constraints result in a high density of dislocations becoming trapped at the segregation network to form dislocation cells in each melt pool. Thermal cycling of volumes below each finally-formed melt pool, from over-printed layers, then additionally leads to the formation of well-defined cell-block structure as a result of biased-dislocation accumulation associated with nascent small orientation variations in just-solidified melt pools. Depth dependent hardness measurements confirm that these cell-block boundaries directly contribute to the mechanical strength of the microstructure observed in interior (bulk) volumes of additively manufactured samples.","PeriodicalId":238,"journal":{"name":"Acta Materialia","volume":"626 1","pages":""},"PeriodicalIF":9.4,"publicationDate":"2025-06-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144319356","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}

引用次数: 0

Elastic softening via crystallographic texture: Decoupling grain size, shape, and orientation effects in phase-transforming polycrystals 晶体织构的弹性软化：相变多晶中晶粒尺寸、形状和取向的去耦效应

IF 8.3 1区材料科学

Acta Materialia Pub Date : 2025-06-18 DOI: 10.1016/j.actamat.2025.121246

Yuxuan Wang , Jianting Li , Cheng-Chao Hu , Yuxuan Chen , Yaodong Yang , Wei-Feng Rao

{"title":"Elastic softening via crystallographic texture: Decoupling grain size, shape, and orientation effects in phase-transforming polycrystals","authors":"Yuxuan Wang , Jianting Li , Cheng-Chao Hu , Yuxuan Chen , Yaodong Yang , Wei-Feng Rao","doi":"10.1016/j.actamat.2025.121246","DOIUrl":"10.1016/j.actamat.2025.121246","url":null,"abstract":"<div><div>The elastic softening of polycrystalline phase-transforming materials (PTMs) is intricately linked to their microstructural characteristics, yet the individual and coupled roles of grain size, shape, and orientation remain inadequately resolved. Here we employed 3D phase-field simulations on an iron-nickel alloy with strong elastic anisotropy to decouple these effects. It was demonstrated that crystallographic texture dominates elastic softening, reducing the modulus by up to 75 % when grains align along soft crystallographic orientations. Grain size exerts negligible influence on the elastic modulus of coarse- and fine-grained PTMs under small loads but critically governs phase transition hysteresis under large deformation. Morphological anisotropy introduced by elongated or flattened geometries of grains modifies the modulus by ∼10 %. Nonlinear interactions between texture and grain morphology further modulate softening magnitudes, deviating from linear superposition predictions. By decoupling these effects, it is suggested that texture engineering via orientation alignment is the most effective pathway for designing PTMs with tailored elastic softening. This work provides a microstructure-property map for designing PTMs with desired elasticity.</div></div>","PeriodicalId":238,"journal":{"name":"Acta Materialia","volume":"296 ","pages":"Article 121246"},"PeriodicalIF":8.3,"publicationDate":"2025-06-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144311679","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}

引用次数: 0

Machine learning of microstructure–property relationships in materials leveraging microstructure representation from foundational vision transformers 利用基础视觉变压器的微观结构表示的材料微结构-性能关系的机器学习

IF 9.4 1区材料科学

Acta Materialia Pub Date : 2025-06-18 DOI: 10.1016/j.actamat.2025.121217

Sheila E. Whitman, Marat I. Latypov

{"title":"Machine learning of microstructure–property relationships in materials leveraging microstructure representation from foundational vision transformers","authors":"Sheila E. Whitman, Marat I. Latypov","doi":"10.1016/j.actamat.2025.121217","DOIUrl":"https://doi.org/10.1016/j.actamat.2025.121217","url":null,"abstract":"Machine learning of microstructure–property relationships from data is an emerging approach in computational materials science. Most existing machine learning efforts focus on the development of task-specific models for each microstructure–property relationship. We propose utilizing pre-trained foundational vision transformers for the extraction of task-agnostic microstructure features and subsequent light-weight machine learning of a microstructure-dependent property. We demonstrate our approach with pre-trained state-of-the-art vision transformers (CLIP, DINOv2, SAM) in two case studies on machine-learning: (i) elastic modulus of two-phase microstructures based on simulations data; and (ii) Vicker’s hardness of Ni-base and Co-base superalloys based on experimental data published in literature. Our results show the potential of foundational vision transformers for robust microstructure representation and efficient machine learning of microstructure–property relationships without the need for expensive task-specific training or fine-tuning of bespoke deep learning models.","PeriodicalId":238,"journal":{"name":"Acta Materialia","volume":"6 1","pages":""},"PeriodicalIF":9.4,"publicationDate":"2025-06-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144311678","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}

引用次数: 0

The origin of strings and rings in the atomic dynamics of disordered systems 无序系统原子动力学中弦和环的起源

IF 8.3 1区材料科学

Acta Materialia Pub Date : 2025-06-17 DOI: 10.1016/j.actamat.2025.121212

Omar Hussein, Yang Li, Yuri Mishin

引用次数: 0

The role of grain boundary character on hydrogen energetics and kinetics in tungsten: Insights from atomic-scale modeling 晶界特征在钨中氢能量学和动力学中的作用：来自原子尺度模型的见解

IF 9.4 1区材料科学

Acta Materialia Pub Date : 2025-06-17 DOI: 10.1016/j.actamat.2025.121267

Xue-Ru Zheng, Xiang-Shan Kong, C.S. Liu, Xiao Zhou

{"title":"The role of grain boundary character on hydrogen energetics and kinetics in tungsten: Insights from atomic-scale modeling","authors":"Xue-Ru Zheng, Xiang-Shan Kong, C.S. Liu, Xiao Zhou","doi":"10.1016/j.actamat.2025.121267","DOIUrl":"https://doi.org/10.1016/j.actamat.2025.121267","url":null,"abstract":"Hydrogen (H) retention in tungsten (W), a critical challenge for its application as a plasma-facing material in nuclear reactors, is strongly influenced by grain boundaries (GBs). However, the precise role of GB in H diffusion and retention, as along with the intricate interactions with H energetics and kinetics, remains poorly understood and contentious yet. In this study, we conduct comprehensive atomistic simulations to explore the effects of GBs on H segregation, desorption, and diffusion in W. Our results reveal that GBs preferentially trap H, with the GB-H binding energies closely related to specific polyhedral structural units. We thoroughly analyze the migration pathways and energy barriers involved in H desorption, determining the critical desorption and decoupling temperatures using a statistical approach. More importantly, the rapid H diffusion channels are identified within GBs that contain discrete dislocation cores and pentagonal bipyramid (PBP) units. Based on these results, we propose a material design strategy that involves tuning GB types and temperature conditions to mitigate H retention. These findings provide essential insights into the energetics and kinetics of GB-H interactions, offering valuable guidance for the design of W-based materials with enhanced resistance to H retention through GB engineering.","PeriodicalId":238,"journal":{"name":"Acta Materialia","volume":"232 1","pages":""},"PeriodicalIF":9.4,"publicationDate":"2025-06-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144311681","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}

引用次数: 0

Crystal symmetry-driven structural design for enhanced thermoelectric performance in lead-free cubic GeTe 提高无铅立方锗热电性能的晶体对称驱动结构设计

IF 8.3 1区材料科学

Acta Materialia Pub Date : 2025-06-17 DOI: 10.1016/j.actamat.2025.121266

Fang Xu , Bo Liu , Ran Ang

{"title":"Crystal symmetry-driven structural design for enhanced thermoelectric performance in lead-free cubic GeTe","authors":"Fang Xu , Bo Liu , Ran Ang","doi":"10.1016/j.actamat.2025.121266","DOIUrl":"10.1016/j.actamat.2025.121266","url":null,"abstract":"<div><div>GeTe-based materials have emerged as promising candidates for medium-temperature thermoelectric (TE) applications. However, their phase transition near ∼700 K significantly degrades mechanical properties. In this study, we present a novel approach to stabilize the cubic rock-salt phase of lead-free GeTe at room temperature through co-doping with Tb and Sb, which completely solves the phase transition problem. Tb substitution at Ge sites not only alters the valence band structure but also promotes the formation of orthorhombic Tb<sub>2</sub>Te<sub>3</sub>, effectively reducing the <em>c</em>/<em>a</em> lattice ratio. Simultaneously, Sb doping optimizes the carrier concentration, enhances band convergence, and suppresses the stereochemical activity of Ge<sup>2+</sup> 4<em>s</em><sup>2</sup> lone pair electrons, thereby improving the overall symmetry of GeTe. The introduction of hierarchical nano- and meso-structures, including nanoprecipitates (e.g., solid-solution point defects, Ge, Tb<sub>2</sub>Te<sub>3</sub>, and Sb<sub>2</sub>Te<sub>3</sub>) and an increased density of grain boundaries, further augments the material's performance. As a result, the optimized composition, Ge<sub>0.89</sub>Tb<sub>0.01</sub>Sb<sub>0.10</sub>Te, achieves a peak <em>ZT</em> of ∼2.0, an average <em>ZT</em> (<em>ZT</em><sub>avg</sub>) of ∼1.24, a theoretical conversion efficiency of ∼16.50%, and a Vickers hardness of ∼203.16 <em>H</em><sub>v</sub>. This study demonstrates that inducing orthorhombic structure and manipulating lone-pair electrons can effectively enhance the crystal symmetry of lead-free GeTe-based materials, offering valuable insights for the development of high-performance cubic-phase GeTe materials.</div></div>","PeriodicalId":238,"journal":{"name":"Acta Materialia","volume":"296 ","pages":"Article 121266"},"PeriodicalIF":8.3,"publicationDate":"2025-06-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144305339","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}

引用次数: 0

Enhancing the activity of 〈c + a〉 dislocations in Mg alloys via high-energy pulsed current 利用高能脉冲电流增强镁合金位错活动性

IF 8.3 1区材料科学

Acta Materialia Pub Date : 2025-06-17 DOI: 10.1016/j.actamat.2025.121268

Yang Yang , Yu Zhang , Chengyu Ding , Guisen Liu , Houyu Ma , Li Jin , Han Ding , Chang Ye , Jian Wang

{"title":"Enhancing the activity of 〈c + a〉 dislocations in Mg alloys via high-energy pulsed current","authors":"Yang Yang , Yu Zhang , Chengyu Ding , Guisen Liu , Houyu Ma , Li Jin , Han Ding , Chang Ye , Jian Wang","doi":"10.1016/j.actamat.2025.121268","DOIUrl":"10.1016/j.actamat.2025.121268","url":null,"abstract":"<div><div>The activation of non-basal slip systems, especially 〈<em>c</em> <em>+</em> <em>a〉</em> dislocations, is crucial for enhancing plasticity of magnesium alloys at room temperature. Based on the concept of current induced local Joule heating along grain boundaries, we examined the effect of pulsed currents on enhancing the uniform elongation of strongly textured AZ31 magnesium alloys at near room temperature. The samples were subjected to uniaxial tension along the RD direction at near room temperature while a continuous current or wide-frequency pulsed current was applied, with careful control of the current parameters to avoid excessively high temperature rises. Using electron backscatter diffraction and two-beam transmission electron microscopy characterization, the textures and dislocations with/without applied pulsed current were analyzed. The uniform elongation is increased while the texture is weakened under pulsed current compared with under constant temperature or continuous current. Combined with numerical simulations, we propose that the enhanced activation of 〈<em>c</em> <em>+</em> <em>a〉</em> dislocations by pulsed currents provides plastic deformation and weakens the texture. This is attributed to the local high temperature generated by low-frequency pulsed currents near defects. These findings provide new insights into controlling the plastic deformation mode of hexagonal metals under near-room temperature conditions, which could have significant implications for the widespread application of such lightweight materials in critical areas.</div></div>","PeriodicalId":238,"journal":{"name":"Acta Materialia","volume":"296 ","pages":"Article 121268"},"PeriodicalIF":8.3,"publicationDate":"2025-06-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144312213","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}

引用次数: 0