Acta Materialia最新文献

{"title":"Ferroelectric grain boundary complexion transitions","authors":"Catherine M. Bishop, K.S.N. Vikrant, R. Edwin García","doi":"10.1016/j.actamat.2025.121043","DOIUrl":"https://doi.org/10.1016/j.actamat.2025.121043","url":null,"abstract":"By starting from equilibrium volumetric and interfacial properties of ferroelectric materials, a thermodynamically-consistent phase field framework incorporating polarization and space charge for polycrystalline ferroelectrics is developed. Building on Cahn’s critical point wetting variational analysis, a series of planar <span><span style=\"\"></span><span data-mathml='<math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow is=\"true\"><mo is=\"true\">[</mo><mn is=\"true\">0</mn><mspace width=\"0.16667em\" is=\"true\" /><mn is=\"true\">0</mn><mspace width=\"0.16667em\" is=\"true\" /><mn is=\"true\">1</mn><mo is=\"true\">]</mo></mrow></math>' role=\"presentation\" style=\"font-size: 90%; display: inline-block; position: relative;\" tabindex=\"0\"><svg aria-hidden=\"true\" focusable=\"false\" height=\"2.779ex\" role=\"img\" style=\"vertical-align: -0.812ex;\" viewbox=\"0 -846.5 2391.8 1196.3\" width=\"5.555ex\" xmlns:xlink=\"http://www.w3.org/1999/xlink\"><g fill=\"currentColor\" stroke=\"currentColor\" stroke-width=\"0\" transform=\"matrix(1 0 0 -1 0 0)\"><g is=\"true\"><g is=\"true\"><use xlink:href=\"#MJMAIN-5B\"></use></g><g is=\"true\" transform=\"translate(278,0)\"><use xlink:href=\"#MJMAIN-30\"></use></g><g is=\"true\"></g><g is=\"true\" transform=\"translate(945,0)\"><use xlink:href=\"#MJMAIN-30\"></use></g><g is=\"true\"></g><g is=\"true\" transform=\"translate(1612,0)\"><use xlink:href=\"#MJMAIN-31\"></use></g><g is=\"true\" transform=\"translate(2113,0)\"><use xlink:href=\"#MJMAIN-5D\"></use></g></g></g></svg><span role=\"presentation\"><math xmlns=\"http://www.w3.org/1998/Math/MathML\"><mrow is=\"true\"><mo is=\"true\">[</mo><mn is=\"true\">0</mn><mspace is=\"true\" width=\"0.16667em\"></mspace><mn is=\"true\">0</mn><mspace is=\"true\" width=\"0.16667em\"></mspace><mn is=\"true\">1</mn><mo is=\"true\">]</mo></mrow></math></span></span><script type=\"math/mml\"><math><mrow is=\"true\"><mo is=\"true\">[</mo><mn is=\"true\">0</mn><mspace width=\"0.16667em\" is=\"true\"></mspace><mn is=\"true\">0</mn><mspace width=\"0.16667em\" is=\"true\"></mspace><mn is=\"true\">1</mn><mo is=\"true\">]</mo></mrow></math></script></span> tilt grain boundaries in tetragonal ferroelectrics in the absence of point defects are investigated. We find that grain boundaries with (i) head-to-tail-like polarization configurations have built in E-fields and undergo order–disorder transformations with decreasing temperature or increasing misorientation and those with (ii) head-to-head-like polarization configurations are paraelectric with no E-field and become more structurally disordered with decreasing temperature or increasing misorientation. Results suggest that ordered and disordered grain boundary complexions can coexist in first order ferroelectrics at all temperatures below the Curie temperature, <span><span style=\"\"></span><span data-mathml='<math xmlns=\"http://www.w3.org/1998/Math/MathML\"><msub is=\"true\"><mrow is=\"true\"><mi is=\"true\">T</mi></mrow><mrow is","PeriodicalId":238,"journal":{"name":"Acta Materialia","volume":"140 1","pages":""},"PeriodicalIF":9.4,"publicationDate":"2025-04-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143872348","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":"Origin of exceptional structural stability in refractory amorphous high-entropy alloys under ion irradiation","authors":"Tianqing Li ,&nbsp;Xinyi Pang ,&nbsp;Yiding Wang ,&nbsp;Xiangdong Ding ,&nbsp;Fei Sun ,&nbsp;Hongxiang Zong ,&nbsp;Jun Sun","doi":"10.1016/j.actamat.2025.121078","DOIUrl":"10.1016/j.actamat.2025.121078","url":null,"abstract":"<div><div>Refractory amorphous high-entropy alloys (RAHEAs) are promising candidates for advanced nuclear coating materials due to their superior structural stability and ion irradiation tolerance. However, the atomic-level irradiation damage mechanisms remain poorly understood. In this work, molecular dynamics (MD) simulations are performed to systematically investigate the ion irradiation responses of Ti(Zr)HfNbTa metallic glasses (MGs) at varying primary knock-on atom (PKA) energies and temperatures. Our results show that the collision cascading behaviors in RAHEAs differs significantly from that in crystalline and conventional metallic glass counterparts. Due to atomic sluggish long-range diffusion and reduced dynamic heterogeneities, RAHEAs exhibit suppressed yet spatially uniform atomic dynamics. This leads to slower PKA energy dissipation and a longer trajectory of displacement cascades, with a smaller cascade-affected zone and more rapid structural recovery rate. These features contribute to high global microstructural stability and low ion irradiation damage. As a result, RAHEAs exhibit less degradation in mechanical performance under ion irradiation. This study provides new insights into the ion irradiation resistance mechanisms of RAHEAs, offering guidance for the development of novel radiation-resistant materials.</div></div>","PeriodicalId":238,"journal":{"name":"Acta Materialia","volume":"292 ","pages":"Article 121078"},"PeriodicalIF":8.3,"publicationDate":"2025-04-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143872347","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":"Phase-field modeling of cavity growth and dislocation climb","authors":"B. Dabas ,&nbsp;A. Ruffini ,&nbsp;Y. Le Bouar ,&nbsp;T. Jourdan ,&nbsp;A. Finel","doi":"10.1016/j.actamat.2025.121040","DOIUrl":"10.1016/j.actamat.2025.121040","url":null,"abstract":"<div><div>An original phase-field model coupling cavity growth, dislocation climb and vacancy diffusion is proposed. The model naturally accounts for elastic interactions between objects while its kinetic equations guarantee that matter is conserved when bulk vacancies are exchanged at the cavity surface or the dislocation core. An original spectral method that drastically reduces simulation time is also proposed in order to efficiently obtain the stationary vacancy concentration profiles during the objects evolution. It is shown how this model can be calibrated in a physically-informed way to reproduce diffusion-mediated cavity growth and dislocation climb under the so called “local equilibrium assumption”. As an application of the model, the microstructural evolution of an annealed irradiated aluminum sample, implying interactions between several cavities and dislocations, is simulated. Non trivial effects regarding the dislocation-induced elastic interactions on the closure kinetics of cavities are notably highlighted.</div></div>","PeriodicalId":238,"journal":{"name":"Acta Materialia","volume":"293 ","pages":"Article 121040"},"PeriodicalIF":8.3,"publicationDate":"2025-04-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143872346","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":"Multiscale modelling with neural network-based crystal plasticity model from meso- to macroscale","authors":"Yuanzhe Hu, Guowei Zhou, Marko Knezevic, Yao Shen, Peidong Wu, Dayong Li","doi":"10.1016/j.actamat.2025.121075","DOIUrl":"https://doi.org/10.1016/j.actamat.2025.121075","url":null,"abstract":"Multiscale simulation plays a pivotal role in macroscopic behavior analysis by incorporating micro-level physical deformation evolutions, which provides valuable insights for materials science and industrial manufacturing. However, its development has remained relatively retarded despite the long-established concept due to the challenge of balancing efficiency and accuracy. To address this issue, the current study introduces a recurrent neural network-based constitutive model as the mesoscale surrogate for crystal plasticity, termed Polycrystalline Linearized Minimal State Cells (PolyLMSC), which comprises two parallel LMSCs to predict both the mechanical response and texture evolution simultaneously. A new texture-mechanics linkage method is proposed based on the Fourier coefficients of generalized spherical harmonic (GSH) functions, where the linearity of Fourier space promotes the PolyLMSC model to extend to different textures. To enhance generalizability across arbitrary loading conditions, arbitrary strain paths with random and diverse variations in incremental size and loading direction are adopted for data generation. During the validation at the single material point, the PolyLMSC model shows good generalization performance across different textures under arbitrary loading. Furthermore, the PolyLMSC model is evaluated through various component-scale simulation cases, illustrating reasonable accuracy at meso- and macroscale predictions with 1∼2 orders of magnitude improvement in computational efficiency compared to conventional crystal plasticity models. The validation results demonstrate the proposed model as a promising candidate for efficient and accurate multiscale simulations, bridging the meso- to macroscales.","PeriodicalId":238,"journal":{"name":"Acta Materialia","volume":"33 1","pages":""},"PeriodicalIF":9.4,"publicationDate":"2025-04-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143862718","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":"Time evolution of Kirkendall porosity in single-phase Ni-based diffusion couples","authors":"Camille Salsi, Julien Lesseur, Daniel Monceau, Clara Desgranges, Thomas Gheno","doi":"10.1016/j.actamat.2025.121022","DOIUrl":"https://doi.org/10.1016/j.actamat.2025.121022","url":null,"abstract":"The development of the Kirkendall porosity was studied in fcc Ni–30Cr/Ni–10Si diffusion couples at 1176 °C using X-ray tomography, optical and scanning electron microscopy, and multicomponent diffusion simulation. Diffusion experiments were interrupted multiple times to monitor the porosity ex situ by tomography. This allowed tracking the position and size of thousands of pores over tens of hours. Pores detected by tomography were also observed by microscopy to determine the surrounding grain structure. The porosity depth profiles (number density, equivalent diameter, area/volume fraction) derived from 2D cross-sectional observations and 3D tomography were compared and the benefits of both methods discussed. Alloys of different grain sizes were used as starting materials to study the influence of the grain boundary density on the spatial pore distribution. Local analysis showed that pore nucleation was not significantly accelerated on grain boundaries compared to the grain interior, but that pore growth was faster along grain boundaries. The time-resolved pore distribution data indicated that the porosity evolved through both pore movement and growth-shrinkage. These mechanisms were discussed in view of the simulated vacancy flux profile.","PeriodicalId":238,"journal":{"name":"Acta Materialia","volume":"37 1","pages":""},"PeriodicalIF":9.4,"publicationDate":"2025-04-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143862752","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":"Thermodynamic analysis and modeling of Pd-Ni-S bulk metallic glass-forming system","authors":"Maryam Rahimi Chegeni, Wenhao Ma, Sascha Riegler, Amirhossein Ghavimi, Magnus Rohde, Fan Yang, Hans Jürgen Seifert, Isabella Gallino, Ralf Busch","doi":"10.1016/j.actamat.2025.121074","DOIUrl":"https://doi.org/10.1016/j.actamat.2025.121074","url":null,"abstract":"This study explores both experimental and computational aspects of the thermophysical properties of the novel ternary BMG-forming Pd-Ni-S system. Unlike more complex quinary BMG-formers, this ternary system's simplicity allows for applying the CALPHAD approach to model the underlying thermodynamics governing glass formation.Experimental investigations include quantifying specific heat capacity and studying crystallization across various compositions critical for generating essential input data. Using a two-state approach, initial modeling of the undercooled liquid and glass is conducted for individual elements and extended to the ternary system. Model predictions are validated against experimental findings and iteratively optimized. Using the parallel tangent method, the Gibbs free energy of crystalline and liquid phases at different compositions are calculated, providing a more accurate estimation of the nucleation driving force of the first forming phase compared to the conventional thermodynamic approach. These calculated driving forces are then used to model the isothermal Time-Temperature-Transformation (TTT) diagrams, and finally for the estimation of the interfacial energy between liquid and crystal during primary crystallization, which plays an important role in the glass-forming ability of this system. The experimental and calculated results are found to be compatible for near-eutectic compositions.","PeriodicalId":238,"journal":{"name":"Acta Materialia","volume":"15 1","pages":""},"PeriodicalIF":9.4,"publicationDate":"2025-04-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143857645","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":"From creep-life prediction to ultra-creep-resistant steel design: An uncertainty-informed machine learning approach","authors":"Chenchong Wang ,&nbsp;Xiaolu Wei ,&nbsp;Sybrand van der Zwaag ,&nbsp;Qiang Wang ,&nbsp;Wei Xu","doi":"10.1016/j.actamat.2025.121073","DOIUrl":"10.1016/j.actamat.2025.121073","url":null,"abstract":"<div><div>In this research a machine learning model incorporating uncertainty to enhance the creep-life prediction and high-throughput design of creep-resistant steel is proposed. The framework integrates key physical metallurgical parameter linked to precipitate coarsening and applies transfer learning to correlate short-time tensile properties with the creep performance, all within a Bayesian convolutional neural network. Unlike conventional machine learning models, which often lack an assessment of prediction credibility, this uncertainty-based approach offers more accurate and stable predictions while also providing a measure of prediction credibility. By combining the model with a genetic algorithm, the framework achieves a balance between creep life optimization and uncertainty, thereby supporting robust alloy design. The validation on newly developed martensitic heat-resistant steels with tolerable prediction uncertainty showed excellent alignment between predicted and experimentally determined creep life, underscoring the effectiveness of the framework. These findings highlight the critical role of uncertainty modeling in advancing machine learning applications for alloy design.</div></div>","PeriodicalId":238,"journal":{"name":"Acta Materialia","volume":"292 ","pages":"Article 121073"},"PeriodicalIF":8.3,"publicationDate":"2025-04-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143857644","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":"Machine learning driven insights into lithiation mechanisms at the silicon-graphite interface within composite electrode","authors":"Bowen Zhang ,&nbsp;Teng Ma ,&nbsp;Niandong He ,&nbsp;Changguo Wang ,&nbsp;Huifeng Tan ,&nbsp;Jiecai Han ,&nbsp;Yuanpeng Liu","doi":"10.1016/j.actamat.2025.121072","DOIUrl":"10.1016/j.actamat.2025.121072","url":null,"abstract":"<div><div>Silicon-graphite composite electrodes are considered as ideal candidates for high-performance lithium-ion batteries due to their outstanding theoretical specific capacity. A comprehensive understanding of the lithiation mechanism at the silicon-graphite interface is crucial for improving battery performance, particularly in terms of enhancing cycling stability and reversible capacity. In this work, we have trained a machine learning potential and performed large-scale molecular simulations to investigate the lithiation mechanisms at individual a-Si, a-Si/graphite-I, and a-Si/graphite-II interfaces. The results demonstrate that the trained potential achieves accuracy comparable to density functional theory, making it well-suited for high-precision simulations of lithiation dynamics in large-scale systems. Our findings reveal that, compared to the reference a-Si system, graphite effectively mitigates direct lithium-silicon contact, reducing interfacial reactions and promoting a diffusion-dominated lithiation process. Notably, the a-Si/graphite-I interface exhibits the fastest lithiation rate while efficiently suppressing the diffusion of silicon atoms toward the lithium source. This confinement facilitates the formation of a dense lithiated phase, significantly minimizing silicon loss and enhancing both the reversible capacity and cycling stability of the electrode. Our study provides valuable theoretical insights for the performance enhancement of silicon-graphite composite electrode materials.</div></div>","PeriodicalId":238,"journal":{"name":"Acta Materialia","volume":"292 ","pages":"Article 121072"},"PeriodicalIF":8.3,"publicationDate":"2025-04-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143857649","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":"Understanding the intrinsic framework of the Hall-Petch relationship of metals from the view of the electronic-structure level","authors":"Xin Li,&nbsp;Wang Gao,&nbsp;Qing Jiang","doi":"10.1016/j.actamat.2025.121071","DOIUrl":"10.1016/j.actamat.2025.121071","url":null,"abstract":"<div><div>The Hall-Petch relationship in the form of <em>σ</em> = <em>σ</em>₀ + <em>kd</em>^−0.5 has been widely used to study the relationship between grain size and yield strength of metals; however, the specific physical factors that affect the coefficients <em>σ</em>₀ and <em>k</em> remain unclear. Here we propose two intrinsic descriptors to determine the coefficients of the Hall-Petch relation across different metals and alloys. Inspired by tight-binding theory, we find that <em>σ</em>₀ strongly depends on the group and period number, valence-electron number and electronegativity, while <em>k</em> is determined by the cohesive energy. Our framework establishes a predictive structure-property relationship for the size-dependent yield strength of various metals, and unravels that both coefficients of the Hall-Petch relationship physically originate from the d-band properties. This novel correlation provides a new perspective for understanding the mechanical strength of metals, which is useful for the design of high-performance alloys.</div></div>","PeriodicalId":238,"journal":{"name":"Acta Materialia","volume":"292 ","pages":"Article 121071"},"PeriodicalIF":8.3,"publicationDate":"2025-04-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143853729","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":"The impact of non-equilibrium vacancies on mobilities and Kirkendall porosity formation in diffusion couples: Experiments and theory for the Cu–Fe–Ni system as a case study","authors":"G. Mohan Muralikrishna ,&nbsp;Neelamegan Esakkiraja ,&nbsp;Julia Kundin ,&nbsp;Frank Hisker ,&nbsp;Jasper Berndt ,&nbsp;Stephan Klemme ,&nbsp;Irina V. Belova ,&nbsp;Graeme E. Murch ,&nbsp;Aloke Paul ,&nbsp;Sergiy V. Divinski","doi":"10.1016/j.actamat.2025.121035","DOIUrl":"10.1016/j.actamat.2025.121035","url":null,"abstract":"<div><div>Recently elaborated tracer-interdiffusion couple approach is used to quantify the differences of atomic mobilities measured in homogeneous alloys with purely entropic driving forces and those determined from diffusion couples under chemical gradients. First, the self-diffusion rates of Fe, Ni and Cu are measured in selected homogeneous alloys of the ternary Cu–Fe–Ni system at 1273 K using the radiotracer method. Following, a novel augmented tracer-interdiffusion couple approach is used with the Cu₅₀Ni₅₀ and Fe₅₀Ni₅₀ binary alloys as end-members and depositing the ⁵⁵Fe and ⁶³Ni radioisotopes at the initial contact plane and at the both external surfaces. The non-equilibrium vacancies are found to enhance the atomic mobilities at 1273 K in the Cu–Fe–Ni system by about 20%. The results confirm a high level of reliability and the reproducibility of the approach for producing highly accurate diffusion data for generating mobility databases. Together with a CALPHAD-like theoretical analysis and thermodynamic factors, these results present a complete data set for the quantitative verification of the theoretical description of diffusion in ternary alloys. The impact of vacancy production on the developed chemical profiles and the Kirkendall effect are analyzed. An agreement between the experimental findings and the theoretical predictions is shown.</div></div>","PeriodicalId":238,"journal":{"name":"Acta Materialia","volume":"292 ","pages":"Article 121035"},"PeriodicalIF":8.3,"publicationDate":"2025-04-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143853700","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}