Acta Materialia最新文献

{"title":"A modified substitutional solution model for describing thermal vacancies","authors":"Cheng-Hui Xia ,&nbsp;Xiao-Gang Lu","doi":"10.1016/j.actamat.2025.121564","DOIUrl":"10.1016/j.actamat.2025.121564","url":null,"abstract":"<div><div>Thermal vacancies are critical structural defects in metals, significantly influencing various material properties, such as diffusivity and thermal conductivity. The Compound Energy Formalism (CEF) has been extensively utilized to describe phases with sublattices. However, researchers have yet to reach a consensus on determining the molar Gibbs energies of vacancies, even when employing the substitutional solution model (SSM) as a single-sublattice CEF model. This is due to challenges in assigning physically meaningful values to the molar Gibbs energy of vacancies without encountering issues such as multiple equilibrium vacancy concentrations and phase stability. In this study, we propose a modified SSM (mSSM) to provide a physically consistent description of vacancies. A comprehensive comparison between the SSM and mSSM is presented. The mSSM allows the molar Gibbs energy of vacancies to be assigned physically meaningful values and enables the derivation of a unique analytical solution for the equilibrium vacancy concentration. It is applied to the FCC phase of the Cu-Ni system to accurately predict vacancy formation energies. Notably, parameters previously determined using the SSM can be directly applied in the mSSM, yielding close results at equilibrium. When vacancies are excluded, the mSSM reduces to the SSM. However, it is advisable to reoptimize parameters related to vacancies in the mSSM, such as the positive molar Gibbs energy of vacancies, to obtain physically meaningful results.</div></div>","PeriodicalId":238,"journal":{"name":"Acta Materialia","volume":"301 ","pages":"Article 121564"},"PeriodicalIF":9.3,"publicationDate":"2025-09-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145089035","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":"Mechanisms of radiation-induced G-phase precipitation in Fe-MnNiSi ferritic model alloys at 400 °C","authors":"Quentin Tencé ,&nbsp;Estelle Meslin ,&nbsp;Isabelle Mouton ,&nbsp;Brigitte Décamps ,&nbsp;Raphaëlle Guillou ,&nbsp;Jean-Luc Béchade ,&nbsp;Erik Elkaim ,&nbsp;Anna Fraczkiewicz ,&nbsp;Maylise Nastar","doi":"10.1016/j.actamat.2025.121502","DOIUrl":"10.1016/j.actamat.2025.121502","url":null,"abstract":"<div><div>A high-purity <span><math><mrow><mtext>Fe-</mtext><mn>0</mn><mo>.</mo><mn>7</mn><mtext>Mn-</mtext><mn>1</mn><mo>.</mo><mn>8</mn><mtext>Ni-</mtext><mn>0</mn><mo>.</mo><mn>8</mn><mtext>Si</mtext></mrow></math></span> model reactor pressure vessel alloy was irradiated with 22.5 MeV Fe^9＋ ions at 400 °C, producing a radiation dose of 1–2 dpa at a depth of <span><math><mrow><mn>1</mn><mspace></mspace><mi>μ</mi><mi>m</mi></mrow></math></span>, following by annealing at the same temperature for up to 34 weeks. Irradiation led to the formation of four Mn-Ni-Si-enriched features: spherical precipitates in the bulk and on dislocation lines, sandwich-like precipitates, and toroidal segregation on dislocation loops. High-resolution transmission electron microscopy and synchrotron X-ray diffraction identified bulk precipitates as G-phase, exhibiting L2<span><math><msub><mrow></mrow><mrow><mn>1</mn></mrow></msub></math></span> symmetry, a cube-on-cube orientation with the matrix, and semi-coherent interfaces. Atom probe tomography showed that the bulk G-phase precipitates have the formula <span><math><mrow><msub><mrow><mtext>Ni</mtext></mrow><mrow><mn>16</mn></mrow></msub><msub><mrow><mfenced><mrow><msub><mrow><mtext>Mn</mtext></mrow><mrow><mi>x</mi></mrow></msub><msub><mrow><mtext>Fe</mtext></mrow><mrow><mn>1</mn><mo>−</mo><mi>x</mi></mrow></msub></mrow></mfenced></mrow><mrow><mn>6</mn></mrow></msub><msub><mrow><mtext>Si</mtext></mrow><mrow><mn>7</mn></mrow></msub></mrow></math></span>, with increased Fe substitution in the Mn sublattice under irradiation. G-phase precipitates exhibited thermodynamic stability during post-irradiation annealing, while sandwich-like phases dissolved, indicating metastability. Irradiation reduces the matrix solubility limit, which is evidenced by the reduced volume fraction of G-phase precipitates observed in post-irradiation annealed samples. Heterogeneous precipitation of the G-phase on dislocation lines likely occurs through radiation-induced segregation (RIS) of Ni, Si, and Mn. Bulk sandwich-like precipitates with a dense Ni-Si-enriched phase in the center are strongly evidenced to form through a two-step mechanism: the SIAs clustering into a dense NiSi phase, followed by the kinetics of vacancy-solute clustering, leading to the precipitation of the less dense G-phase.</div></div>","PeriodicalId":238,"journal":{"name":"Acta Materialia","volume":"301 ","pages":"Article 121502"},"PeriodicalIF":9.3,"publicationDate":"2025-09-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145089032","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":"Effect of Sc additions on precipitation behavior and creep- and coarsening resistance of a cast Al-4.5Cu-0.3Mg-0.4Ag (wt%) alloy","authors":"Ismael E. Coello ,&nbsp;Clement N. Ekaputra ,&nbsp;Xiaobing Hu ,&nbsp;Jon-Erik Mogonye ,&nbsp;David C. Dunand","doi":"10.1016/j.actamat.2025.121567","DOIUrl":"10.1016/j.actamat.2025.121567","url":null,"abstract":"<div><div>The effects of solidification rates and solutionizing temperatures on V-phase (Al₈Cu₄Sc) nanoprecipitate formation and subsequent mechanical properties in a cast Al-4.5Cu-0.3Mg-0.4Ag-0.3Sc (wt%) alloy are evaluated. After solutionizing, Ω-Al₂Cu precipitates are formed upon aging at 185 °C and then transformed into Al₈Cu₄Sc V-phase precipitates at 400 °C, showing high coarsening resistance. Avoiding Al_8-xCu_4+xSc W-phase precipitation during solidification is crucial, as this phase reduces the concentration of Cu and Sc available in the matrix for Al₂Cu Ω-precipitation at 185 °C and the subsequent final formation of V-precipitates at 400 °C, affecting microhardness at ambient temperature and creep strength at 400 °C. Solutionizing temperatures between 580 and 600 °C dissolve the undesirable W-phase but form large stable θ-Al₂Cu phases, which also scavenge Cu. Furthermore, the W-phase was observed both under relatively fast solidification in a graphite mold and very slow solidification in a furnace, and the microhardness was similar under the two casting conditions. Similarly, adding 0.15Si wt% does not impact the mechanical properties of the alloy. These findings suggest that Al-Cu alloys with V-phase precipitates have promising potential for high-temperature applications, although further study of the processing techniques is necessary to fully utilize their capabilities.</div></div>","PeriodicalId":238,"journal":{"name":"Acta Materialia","volume":"301 ","pages":"Article 121567"},"PeriodicalIF":9.3,"publicationDate":"2025-09-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145089061","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 simulations of precipitation induced high dissipative superelasticity at low temperatures in shape memory alloys","authors":"Tianjiao Dong ,&nbsp;Chuanxin Liang ,&nbsp;Xuesong Pei,&nbsp;Jianwei Li,&nbsp;Dong Wang","doi":"10.1016/j.actamat.2025.121569","DOIUrl":"10.1016/j.actamat.2025.121569","url":null,"abstract":"<div><div>Shape memory alloys (SMAs) typically lose superelasticity completely below the martensitic transformation finish temperature (<em>M</em>_f) due to detwinning-dominated deformation, which limits their reversible strain capabilities under loading and unloading. Here, using phase-field simulations, we introduce a novel mechanism for precipitation-induced reversible martensitic domain switching to achieve superelasticity below <em>M</em>_f. This mechanism enables precise control over energy dissipation and recoverable strain by tuning precipitation configurations, to transform the behavior of SMAs at low temperatures. Remarkably, we demonstrate that gradient-distributed, variant-selective precipitate condition can resolve the challenge of combining high superelasticity with significant dissipation in martensitic transformations below <em>M</em>_f. Furthermore, our simulations reveal that the critical stress for superelasticity at low temperatures deviates from the traditional Clausius-Clapeyron relationship, due to recoverable domain switching between different martensitic variants. Further analysis reveals that the recoverable domain switching at low temperatures is driven by an intrinsic restoring force arising from the confinement between short-range ordered (SRO) martensitic domain regions and long-range ordered (LRO) martensitic domain regions, induced by gradient-distributed, variant-selective precipitate conditions. This confinement stabilizes specific martensitic variants, enabling significant recoverable strain during loading and unloading, which in turn contributes to the observed high energy dissipation. Our work provides a new strategy for enhancing the functionality and versatility of SMAs in demanding environments.</div></div>","PeriodicalId":238,"journal":{"name":"Acta Materialia","volume":"301 ","pages":"Article 121569"},"PeriodicalIF":9.3,"publicationDate":"2025-09-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145089034","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 model of full thermodynamic stabilization of nanocrystalline alloys","authors":"Omar Hussein,&nbsp;Yuri Mishin","doi":"10.1016/j.actamat.2025.121545","DOIUrl":"10.1016/j.actamat.2025.121545","url":null,"abstract":"<div><div>We propose a model of a polycrystalline alloy combining the Potts model for grain orientations with a lattice-gas model for solute thermodynamics and diffusion. The alloy evolution with this model is implemented by kinetic Monte Carlo simulations with nonlinear transition barriers between microstates. The model is applied to investigate the long-standing question of whether grain boundary (GB) segregation of an appropriate solute can drive the GB free energy to zero, creating a fully stabilized polycrystalline state with a finite grain size. The model reproduces stable polycrystalline states under certain conditions, provided the solute–solute interactions are repulsive. The material’s structure minimizing the total free energy is not static. It exists in a state of dynamic equilibrium between the competing processes of grain growth and grain refinement. The alloy eliminates triple junctions by forming a set of smaller grains embedded into a larger matrix grain. It is predicted that, if a fully stabilized nanocrystalline state is realized experimentally, it will look very different from the conventional (unstable) nanocrystalline materials.</div></div>","PeriodicalId":238,"journal":{"name":"Acta Materialia","volume":"301 ","pages":"Article 121545"},"PeriodicalIF":9.3,"publicationDate":"2025-09-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145089033","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":"Self-supervised learning for glass composition screening","authors":"Meijing Chen ,&nbsp;Bin Liu ,&nbsp;Ying Liu ,&nbsp;Tianrui Li","doi":"10.1016/j.actamat.2025.121509","DOIUrl":"10.1016/j.actamat.2025.121509","url":null,"abstract":"<div><div>Glass finds broad application across optoelectronics, biomedical engineering, and architectural engineering, but the inherent complexity inherent to multicomponent systems creates substantial challenges in the screening of glass compositions with target properties. Current supervised learning methods for this task rely heavily on large amounts of high-quality data and are prone to overfitting on noisy samples, which limits their generalization ability. In this work, we propose a novel self-supervised learning framework designed specifically for screening glass compositions within pre-defined glass transition temperature ranges. We reformulate the screening task as a classification problem, aiming to predict whether the glass transition temperature of a given composition falls within a target interval. To improve the model’s robustness to noise, we introduce an innovative data augmentation strategy grounded in asymptotic theory. Additionally, we present <em>DeepGlassNet</em>, a dedicated network architecture developed to capture and analyze the complex interactions among constituent elements in glass compositions. This architecture is integrated into our self-supervised framework to optimize the Area Under Curve (AUC) classification metric. Experimental results demonstrate that <em>DeepGlassNet</em> achieves superior screening accuracy compared to traditional methods and exhibits strong adaptability to other composition-related screening tasks. This study not only provides an efficient methodology for designing multicomponent glasses but also establishes a foundation for applying self-supervised learning in material discovery. Code and data are available at: <span><span>https://github.com/liubin06/DeepGlassNet</span><svg><path></path></svg></span>.</div></div>","PeriodicalId":238,"journal":{"name":"Acta Materialia","volume":"301 ","pages":"Article 121509"},"PeriodicalIF":9.3,"publicationDate":"2025-09-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145089060","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":"Sensitivity of the viscoplasticity of polycrystals to porosity and pore-to-crystal size ratio","authors":"Louis Védrine ,&nbsp;Pascal Hagenmuller ,&nbsp;Lionel Gélébart ,&nbsp;Maurine Montagnat ,&nbsp;Henning Löwe","doi":"10.1016/j.actamat.2025.121507","DOIUrl":"10.1016/j.actamat.2025.121507","url":null,"abstract":"<div><div>Porous polycrystals are composed of pores and sintered crystals. Understanding their viscoplastic behaviour is crucial for predicting the mechanical performance of manufactured materials or the evolution of geological components. Their viscoplasticity intuitively depends on the shape of the solid matrix and how it is divided into individual crystals. Previous studies have primarily focused on limiting cases with low porosities or extreme pore-to-crystal size ratios. In this study, we use numerical full-field simulations on three-dimensional porous microstructures, combined with a crystal plasticity model, to explore how polycrystal viscoplasticity is affected by both geometric and crystalline structures. We use ice and its porous form, snow, as model materials. Our findings demonstrate that the homogenised strain rate <span><math><mover><mrow><mi>ϵ</mi></mrow><mrow><mo>̇</mo></mrow></mover></math></span> fits a power law of stress <span><math><mi>σ</mi></math></span> as <span><math><mrow><mover><mrow><mi>ϵ</mi></mrow><mrow><mo>̇</mo></mrow></mover><mo>=</mo><msup><mrow><mfenced><mrow><mfrac><mrow><mi>σ</mi></mrow><mrow><msub><mrow><mi>σ</mi></mrow><mrow><mn>0</mn></mrow></msub></mrow></mfrac></mrow></mfenced></mrow><mrow><mi>n</mi></mrow></msup></mrow></math></span> s⁻¹ with <span><math><msub><mrow><mi>σ</mi></mrow><mrow><mn>0</mn></mrow></msub></math></span> the reference stress and <span><math><mi>n</mi></math></span> the stress exponent. Notably, we show that the reference stress is determined solely by the geometric structure, while the stress exponent is influenced by both the geometric and crystalline structures. Specifically, the stress exponent is governed by the geometric frustration of the crystals caused by their neighbours, which modulates dislocation creep across different slip systems. By defining the pore-to-crystal size ratio as the area ratio between the crystal boundary and the free surface, we provide a coherent framework for understanding these interactions. This study clarifies the transitions in viscoplastic behaviour with varying porosity, avoiding the need for additional mechanisms and offering valuable insights into porous polycrystal viscoplasticity.</div></div>","PeriodicalId":238,"journal":{"name":"Acta Materialia","volume":"301 ","pages":"Article 121507"},"PeriodicalIF":9.3,"publicationDate":"2025-09-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145089063","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":"Maximized cation size disorder driven phonon engineering in high-entropy pyrochlores of La2(Zr,Ce,Hf,Sn,Ti)2O7","authors":"Weiran Zhang,&nbsp;Jinping Du,&nbsp;Chenyi Xie,&nbsp;Duan Li,&nbsp;Rongjun Liu,&nbsp;Yanfei Wang","doi":"10.1016/j.actamat.2025.121563","DOIUrl":"10.1016/j.actamat.2025.121563","url":null,"abstract":"<div><div>It is crucial to develop low thermal conductivity(<em>k</em>) materials for thermal barrier coatings of next-generation aero-engines. Through a size disorder oriented approach, novel B-site non-equalmolar high-entropy pyrochlores of La₂(Zr,Ce,Hf,Sn,Ti)₂O₇ have been designed and successfully synthesized, which exhibits a combination of desirable thermophysical properties, i.e. thermal conductivities reaching 1.46 W·m^-1·K^-1, approximately 33% lower than those of La₂Zr₂O₇. The phonon scattering prediction and fitting model under point defect influence along with thermal radiation effects were systematically investigated, elucidating the phonon scattering mechanisms and the critical roles of cation size disorder (δ_B) in thermal conductivity reduction. Furthermore, an improved model has been developed to accurately depict the full-temperature-range thermal conductivity, revealing the detailed thermal transport processes and characteristics in the high-entropy ceramic La₂(Zr,Ce,Hf,Sn,Ti)₂O₇ across the entire temperature range.</div></div>","PeriodicalId":238,"journal":{"name":"Acta Materialia","volume":"301 ","pages":"Article 121563"},"PeriodicalIF":9.3,"publicationDate":"2025-09-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145084362","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":"Achieving superior thermoelectric performance in N-type SnS-based polycrystals by regulating donor dopability and phonon propagation","authors":"Hong Wu ,&nbsp;Chun Yan ,&nbsp;Peng Chen ,&nbsp;Shuai Wu ,&nbsp;Xiangnan Gong ,&nbsp;Bin Zhang ,&nbsp;Guiwen Wang ,&nbsp;Hanjun Zou ,&nbsp;Yanci Yan ,&nbsp;Guangqian Ding ,&nbsp;Jun Liu ,&nbsp;Guang Han ,&nbsp;Guoyu Wang ,&nbsp;Xu Lu ,&nbsp;Dengfeng Li ,&nbsp;Xiaoyuan Zhou","doi":"10.1016/j.actamat.2025.121566","DOIUrl":"10.1016/j.actamat.2025.121566","url":null,"abstract":"<div><div>Recent advancements in <em>p</em>-type SnS-based compounds have highlighted their potential for thermoelectric applications. Nevertheless, the thermoelectric properties of their <em>n</em>-type counterparts lag behind and have been seldom investigated to date, primarily owing to intrinsic Sn vacancies and limited donor dopability, which largely hinders the development of all SnS-based thermoelectric modules. Here, an effective doping strategy is proposed in <em>n</em>-type SnS-based polycrystals by incorporating PbSe along with a donor Br dopant. The electron concentration and power factor of PbSe alloyed compounds outperforms that of the matrix sample, being primarily credited to the improved dopability of Br dopant arising from the lower formation energy of Br dopant in the alloyed samples, as verified by first-principles calculations. Furthermore, the incorporation of PbSe remarkably diminishes the lattice thermal conductivity of the SnS-based materials, resulting from depressed phonon velocity, strengthened lattice anharmonicity and introduction of massive point defects. Consequently, an outstanding maximum <em>zT</em> value of ∼1.25 at 873 K, along with a decent average <em>zT</em> of ∼0.45 from 323 K to 873 K is attained in <em>n</em>-type 2.5 %PbBr₂-doped (SnS)_0.6(PbSe)_0.4 polycrystalline sample, representing record-high values in <em>n</em>-type SnS-based compounds. This research not only reveals that the optimal <em>n</em>-type SnS-based polycrystals are promising candidates for thermoelectric applications, but also offers insights into overcoming the doping bottleneck in thermoelectric materials.</div></div>","PeriodicalId":238,"journal":{"name":"Acta Materialia","volume":"301 ","pages":"Article 121566"},"PeriodicalIF":9.3,"publicationDate":"2025-09-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145089062","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":"Unlocking superior fracture resistance in micro-ceramics for architected meta-materials via ALD stress engineering","authors":"Wenjuan Cheng ,&nbsp;Edoardo Rossi ,&nbsp;Jens Bauer ,&nbsp;Jose Paolo Martins ,&nbsp;Raphael Guillemet ,&nbsp;Laszlo Pethö ,&nbsp;Johann Michler ,&nbsp;Marco Sebastiani","doi":"10.1016/j.actamat.2025.121474","DOIUrl":"10.1016/j.actamat.2025.121474","url":null,"abstract":"<div><div>Micro- and nano-architected metamaterials exhibit remarkable mechanical properties, particularly damage tolerance from the interplay between design and material properties, yet their fracture mechanisms remain poorly understood. Strategies to tailor toughness in response to the anisotropic stress distributions experienced are lacking. Here, we demonstrate a novel approach to enhance the fracture toughness of micro-trusses by up to 165% via interface engineering, leveraging the high surface-to-volume ratios in these materials. We investigate the role of residual stress induced by Atomic Layer Deposition (ALD) on fracture behavior using cohesive-zone finite element simulations and advanced experimental techniques, including pillar-splitting indentation cracking and advanced residual stress measurements. Experiments were conducted on fused silica micro-pillars (fabricated via deep reactive ion etching) and glassy carbon micro-pillars (produced via two-photon polymerization and pyrolysis), coated with ALD Al<span><math><msub><mrow></mrow><mrow><mn>2</mn></mrow></msub></math></span>O<span><math><msub><mrow></mrow><mrow><mn>3</mn></mrow></msub></math></span> or ZnO thin films. Our results reveal that median crack geometry combined with tensile residual stress in the coating enhances apparent toughness by inducing beneficial compressive stress in the substrate. Due to differences in crack morphology, Al<span><math><msub><mrow></mrow><mrow><mn>2</mn></mrow></msub></math></span>O<span><math><msub><mrow></mrow><mrow><mn>3</mn></mrow></msub></math></span> coatings increase the toughness of fused silica by 165% but reduce that of glassy carbon. This study establishes ALD-induced stress modulation as a powerful tool for optimizing fracture resistance in micro-architected ceramics.</div></div>","PeriodicalId":238,"journal":{"name":"Acta Materialia","volume":"301 ","pages":"Article 121474"},"PeriodicalIF":9.3,"publicationDate":"2025-09-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145084389","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}