Acta Materialia最新文献

{"title":"NiTiHf high-temperature shape memory alloy fabricated via laser powder bed fusion showing fully recoverable actuation under tensile stress","authors":"Hongwei Ma ,&nbsp;Orsolya Molnárová ,&nbsp;Petr Šittner ,&nbsp;Haizhou Lu ,&nbsp;Weisi Cai ,&nbsp;Eduardo Alarcón ,&nbsp;Jaromír Kopeček ,&nbsp;Luděk Heller ,&nbsp;Limei Kang ,&nbsp;Chao Yang","doi":"10.1016/j.actamat.2025.121562","DOIUrl":"10.1016/j.actamat.2025.121562","url":null,"abstract":"<div><div>NiTiHf high-temperature shape memory alloys (HTSMAs) fabricated via laser powder bed fusion (LPBF) suffer from poor tensile strength preventing their successful use in engineering applications. We managed to fabricate NiTiHf HTSMA showing tensile actuation under stresses up to 500 MPa in the temperature range 250–350 °C. A tensile strength of 821 MPa, an actuation strain 2.34 % under 300 MPa tensile stress with negligible irrecoverable plastic strain, and fracture upon cooling under 600 MPa tensile stress are the best values reported so far for LPBF-fabricated NiTiHf HTSMAs in the literature. The enhanced tensile strength reaching half of the strength of the conventional cast and thermomechanically processed NiTiHf HTSMAs was attributed to the lack of micropores (porosity 0.02 %). The tensile actuation performance is claimed to be facilitated by the strengthening effect from homogeneously distributed oxide nanoparticles introduced naturally by the LPBF fabrication. The oxide nanoparticles decrease the size of domains of (001) compound twinned martensite created by the forward martensitic transformation upon cooling under stress, which reduces actuation strain but also suppresses dislocation slip in martensite. This dimensional strengthening mechanism lowers actuation strain but increases cyclic stability of the actuation response of the LPBF NiTiHf HTSMA.</div></div>","PeriodicalId":238,"journal":{"name":"Acta Materialia","volume":"301 ","pages":"Article 121562"},"PeriodicalIF":9.3,"publicationDate":"2025-09-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145084388","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 stress on Laves phase precipitation in creep ruptured Grade 92 ferritic martensitic steel characterized by a novel accessible method","authors":"Emily R. Proehl ,&nbsp;Weicheng Zhong ,&nbsp;David J. Sprouster ,&nbsp;Calvin R. Lear ,&nbsp;Matthew M. Schneider ,&nbsp;Chad M. Parish ,&nbsp;Benjamin P. Eftink ,&nbsp;Lance L. Snead ,&nbsp;Steven J. Zinkle ,&nbsp;Lizhen Tan","doi":"10.1016/j.actamat.2025.121559","DOIUrl":"10.1016/j.actamat.2025.121559","url":null,"abstract":"<div><div>At high temperature conditions relevant to fossil and nuclear energy plants, Laves phase (Fe₂X, X=Mo, W) precipitation is observed in common ferritic martensitic (FM) structural steels, with various reported effects on creep behavior. Despite being valuable metrics to correlate with mechanical properties and other precipitate phases, the volume fraction and number density of Laves phase precipitates has been difficult to quantify accurately using common techniques such as transmission electron microscopy (TEM) due to the relatively large size (∼0.25 μm) and low number density (∼10¹¹ cm⁻³) of Laves precipitates. To address this characterization challenge, we developed and demonstrated a high-throughput and widely accessible method to quantify the volume fraction and number density of the Laves phase based on scanning electron microscope (SEM) images with a backscattered electron signal and the information depth (<em>ID</em>) of backscattered electrons. We applied this new technique in creep ruptured Grade 92 FM steel to study the effect of Laves phase on creep properties and determine the influence of stress on Laves phase precipitation. The quantitative accuracy of the SEM-based volume fraction and number density values was verified using synchrotron high energy X-ray diffraction and serial sectioning tomography. Stress did not significantly affect the Laves phase size or volume fraction during creep testing at 550 – 650°C and stress levels of 90 – 260 MPa (vs. unstressed conditions). Conversely, a moderate but statistically significant stress-enhanced increase in Laves phase number density, corresponding to an increase in nucleation rate, occurred during creep exposure above 110 MPa.</div></div>","PeriodicalId":238,"journal":{"name":"Acta Materialia","volume":"301 ","pages":"Article 121559"},"PeriodicalIF":9.3,"publicationDate":"2025-09-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145263091","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 radiation-induced segregation on the point-defect absorption by surfaces, dislocations, and cavities in dilute BCC Fe-based alloys","authors":"Liangzhao Huang,&nbsp;Thomas Schuler,&nbsp;Maylise Nastar","doi":"10.1016/j.actamat.2025.121533","DOIUrl":"10.1016/j.actamat.2025.121533","url":null,"abstract":"<div><div>The evolution of microstructures under irradiation is driven by the interaction of point defects (PDs) with structural sinks, such as surfaces, dislocations, and cavities. This study investigates the effect of solute radiation-induced segregation (RIS) on the sink strengths of these defects in dilute BCC Fe-based alloys containing Cr, Cu, Si, and Ni. Using the Onsager formalism, PD and solute fluxes were computed to derive sink strengths and absorption biases as functions of solute concentration. The results reveal that adding Cu, Si, and Ni significantly reduces sink bias, with Ni having the strongest impact. Unlike pure Fe, surfaces in Fe-X alloys exhibit a vacancy absorption preference. Notably, Ni decreases dislocation and cavity biases, altering the point-defect absorption preference of cavities at high Ni concentrations. Applying these findings to a mean-field rate model provides insights into the cavity growth of Fe-based alloys under irradiation, in line with available experimental observations.</div></div>","PeriodicalId":238,"journal":{"name":"Acta Materialia","volume":"301 ","pages":"Article 121533"},"PeriodicalIF":9.3,"publicationDate":"2025-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145072282","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":"Atomistic understanding of chlorine ingress into compact and wide-open grain boundaries of TiN","authors":"You-Qi Zhou ,&nbsp;Jiachang Bi ,&nbsp;Zhangyuan Guo ,&nbsp;Min Ge ,&nbsp;Jin-Tao Ye ,&nbsp;Yanwei Cao ,&nbsp;Liang-Feng Huang","doi":"10.1016/j.actamat.2025.121505","DOIUrl":"10.1016/j.actamat.2025.121505","url":null,"abstract":"<div><div>The ingress of corrossive Cl ions into the grain boundaries of TiN widely leads to the degradation of numerous realistic protective/functional coatings. The atomistic nature of the interaction between Cl ion and various coexistent grain boundaries in TiN coatings makes it challenging to precisely understand, predict, and control the Cl-ion behaviors. Here, the surface adsorption and inward diffusion of Cl ion on/in many prototypical grain boundaries, i.e., two compact <span><math><mrow><mi>Σ</mi><mn>3</mn><mrow><mo>{</mo><mn>112</mn><mo>}</mo></mrow><mrow><mo>〈</mo><mn>110</mn><mo>〉</mo></mrow></mrow></math></span> twins and four wide-open intergranular boundaries (plus another four doped with oxygen), are studied using first-principles calculations. The active surface adsorption of Cl ion on the exposed grain boundaries is revealed by the low adsorption free energies, and the fast (blocked) Cl-ion diffusion trends on the intergranular-boundary walls (in the twin boundaries) are discovered and quantified by the calculated diffusion barriers and coefficients. The ionic-bonding and lattice-deformation mechanisms that jointly govern these kinetic trends are established by our electronic-structure analysis method. The fast Cl-ion ingress into wide-open intergranular boundaries is also portrayed by a multiscale simulation using Fick’s second law, and many previous saline-corrosion experiments on various TiN coatings are unifiedly explained. The strong blocking effect of compact twin boundaries against the Cl-ion ingress is further validated by our hydrochloric-corrosion experiment on a highly-twinned TiN nanofilm, which is precisely characterized by the X-ray reflectometry and electron microscopy techniques. The TiN nanofilm still encounters the corrosive surface adsorption of Cl ions, but the identified corrosion manner (pitting-initiated uniform thinning) presents a very low corrosion rate of <span><math><mrow><mn>2</mn><mo>.</mo><mn>5</mn><mo>×</mo><mn>1</mn><msup><mrow><mn>0</mn></mrow><mrow><mo>−</mo><mn>3</mn></mrow></msup></mrow></math></span> mm/year.</div></div>","PeriodicalId":238,"journal":{"name":"Acta Materialia","volume":"301 ","pages":"Article 121505"},"PeriodicalIF":9.3,"publicationDate":"2025-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145103736","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":"High-pressure phase and dual sulfur-oxygen vacancy induction in CdS-TiO2 heterojunctions for multifunctional photocatalytic applications","authors":"Thanh Tam Nguyen ,&nbsp;Kaveh Edalati","doi":"10.1016/j.actamat.2025.121555","DOIUrl":"10.1016/j.actamat.2025.121555","url":null,"abstract":"<div><div>The discovery of visible-light-active photocatalysts that operate without noble-metal co-catalysts remains a major bottleneck for environmental remediation and sustainable energy conversion. In the current investigation, a CdS-TiO₂ heterojunction is synthesized via a high-pressure torsion process at ambient temperature, integrating multiple beneficial features for photocatalysis: a high-pressure TiO₂ columbite phase with enhanced surface activity, dual sulfur and oxygen vacancies that increase light absorption and provide catalytic sites, and multiphase heterojunctions that promote charge separation and suppress recombination. These structural advantages lead to outstanding photocatalytic performance across different key applications: (i) efficient tetracycline antibiotic degradation under visible light without a co-catalyst, (ii) hydrogen production without a co-catalyst, (iii) hydrogen generation at a rate five times higher than TiO₂ with platinum co-catalyst addition, and (iv) CO₂ photoreduction with an activity 38 times greater than TiO₂ without co-catalyst. These results highlight dual-vacancy formation and high-pressure phase incorporation in heterostructured catalysts as an effective strategy for designing multifunctional, stable and low-band-gap photocatalysts for environmental and energy-related applications.</div></div>","PeriodicalId":238,"journal":{"name":"Acta Materialia","volume":"301 ","pages":"Article 121555"},"PeriodicalIF":9.3,"publicationDate":"2025-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145072281","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":"Concise magnetic model for thermodynamic calculations of iron from 0 to 1800 K","authors":"S.M.C. van Bohemen","doi":"10.1016/j.actamat.2025.121557","DOIUrl":"10.1016/j.actamat.2025.121557","url":null,"abstract":"<div><div>The proposed magnetic model represents magnetic entropy using two exponential functions: one for long-range order below the transition temperature and another for short-range order above it. This approach ensures that both the magnetic entropy and its temperature derivative approach zero smoothly as temperature nears absolute zero. Differentiating this expression yields a magnetic heat capacity curve with a lambda peak, defined by two adjustable parameters that control its temperature dependence on either side of the transition. This magnetic contribution is integrated with established components of heat capacity, including electronic, harmonic, and anharmonic lattice terms. The overall thermodynamic model was optimized using experimental data for bcc and fcc iron, encompassing transition temperatures, heat capacity measurements from 10 to 1800 K, enthalpy differences, Bohr magneton values, and the magnetic enthalpy fraction attributed to short-range order.</div></div>","PeriodicalId":238,"journal":{"name":"Acta Materialia","volume":"301 ","pages":"Article 121557"},"PeriodicalIF":9.3,"publicationDate":"2025-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145072294","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 quantitative criterion for evidencing predicted compounds in high-throughput powder X-ray diffraction data: Illustration with half-antiperovskite","authors":"Kyoka Nagashima, Peter Klavins, Valentin Taufour","doi":"10.1016/j.actamat.2025.121525","DOIUrl":"https://doi.org/10.1016/j.actamat.2025.121525","url":null,"abstract":"We introduce a simple, fast-paced analysis method for powder x-ray diffraction data to obtain a quantitative distinction between existing and likely non-existing phases. We demonstrate the method with our synthesis attempts of several previously predicted half-antiperovskites (HAPs), with stoichiometry M&lt;span&gt;&lt;span style=\"\"&gt;&lt;/span&gt;&lt;span data-mathml='&lt;math xmlns=\"http://www.w3.org/1998/Math/MathML\"&gt;&lt;msub is=\"true\"&gt;&lt;mrow is=\"true\" /&gt;&lt;mrow is=\"true\"&gt;&lt;mn is=\"true\"&gt;3&lt;/mn&gt;&lt;/mrow&gt;&lt;/msub&gt;&lt;/math&gt;' role=\"presentation\" style=\"font-size: 90%; display: inline-block; position: relative;\" tabindex=\"0\"&gt;&lt;svg aria-hidden=\"true\" focusable=\"false\" height=\"1.509ex\" role=\"img\" style=\"vertical-align: -0.582ex;\" viewbox=\"0 -399.4 453.9 649.8\" width=\"1.054ex\" xmlns:xlink=\"http://www.w3.org/1999/xlink\"&gt;&lt;g fill=\"currentColor\" stroke=\"currentColor\" stroke-width=\"0\" transform=\"matrix(1 0 0 -1 0 0)\"&gt;&lt;g is=\"true\"&gt;&lt;g is=\"true\"&gt;&lt;/g&gt;&lt;g is=\"true\" transform=\"translate(0,-150)\"&gt;&lt;g is=\"true\"&gt;&lt;use transform=\"scale(0.707)\" xlink:href=\"#MJMAIN-33\"&gt;&lt;/use&gt;&lt;/g&gt;&lt;/g&gt;&lt;/g&gt;&lt;/g&gt;&lt;/svg&gt;&lt;span role=\"presentation\"&gt;&lt;math xmlns=\"http://www.w3.org/1998/Math/MathML\"&gt;&lt;msub is=\"true\"&gt;&lt;mrow is=\"true\"&gt;&lt;/mrow&gt;&lt;mrow is=\"true\"&gt;&lt;mn is=\"true\"&gt;3&lt;/mn&gt;&lt;/mrow&gt;&lt;/msub&gt;&lt;/math&gt;&lt;/span&gt;&lt;/span&gt;&lt;script type=\"math/mml\"&gt;&lt;math&gt;&lt;msub is=\"true\"&gt;&lt;mrow is=\"true\"&gt;&lt;/mrow&gt;&lt;mrow is=\"true\"&gt;&lt;mn is=\"true\"&gt;3&lt;/mn&gt;&lt;/mrow&gt;&lt;/msub&gt;&lt;/math&gt;&lt;/script&gt;&lt;/span&gt;Z&lt;span&gt;&lt;span style=\"\"&gt;&lt;/span&gt;&lt;span data-mathml='&lt;math xmlns=\"http://www.w3.org/1998/Math/MathML\"&gt;&lt;msub is=\"true\"&gt;&lt;mrow is=\"true\" /&gt;&lt;mrow is=\"true\"&gt;&lt;mn is=\"true\"&gt;2&lt;/mn&gt;&lt;/mrow&gt;&lt;/msub&gt;&lt;/math&gt;' role=\"presentation\" style=\"font-size: 90%; display: inline-block; position: relative;\" tabindex=\"0\"&gt;&lt;svg aria-hidden=\"true\" focusable=\"false\" height=\"1.509ex\" role=\"img\" style=\"vertical-align: -0.582ex;\" viewbox=\"0 -399.4 453.9 649.8\" width=\"1.054ex\" xmlns:xlink=\"http://www.w3.org/1999/xlink\"&gt;&lt;g fill=\"currentColor\" stroke=\"currentColor\" stroke-width=\"0\" transform=\"matrix(1 0 0 -1 0 0)\"&gt;&lt;g is=\"true\"&gt;&lt;g is=\"true\"&gt;&lt;/g&gt;&lt;g is=\"true\" transform=\"translate(0,-150)\"&gt;&lt;g is=\"true\"&gt;&lt;use transform=\"scale(0.707)\" xlink:href=\"#MJMAIN-32\"&gt;&lt;/use&gt;&lt;/g&gt;&lt;/g&gt;&lt;/g&gt;&lt;/g&gt;&lt;/svg&gt;&lt;span role=\"presentation\"&gt;&lt;math xmlns=\"http://www.w3.org/1998/Math/MathML\"&gt;&lt;msub is=\"true\"&gt;&lt;mrow is=\"true\"&gt;&lt;/mrow&gt;&lt;mrow is=\"true\"&gt;&lt;mn is=\"true\"&gt;2&lt;/mn&gt;&lt;/mrow&gt;&lt;/msub&gt;&lt;/math&gt;&lt;/span&gt;&lt;/span&gt;&lt;script type=\"math/mml\"&gt;&lt;math&gt;&lt;msub is=\"true\"&gt;&lt;mrow is=\"true\"&gt;&lt;/mrow&gt;&lt;mrow is=\"true\"&gt;&lt;mn is=\"true\"&gt;2&lt;/mn&gt;&lt;/mrow&gt;&lt;/msub&gt;&lt;/math&gt;&lt;/script&gt;&lt;/span&gt;X&lt;span&gt;&lt;span style=\"\"&gt;&lt;/span&gt;&lt;span data-mathml='&lt;math xmlns=\"http://www.w3.org/1998/Math/MathML\"&gt;&lt;msub is=\"true\"&gt;&lt;mrow is=\"true\" /&gt;&lt;mrow is=\"true\"&gt;&lt;mn is=\"true\"&gt;2&lt;/mn&gt;&lt;/mrow&gt;&lt;/msub&gt;&lt;/math&gt;' role=\"presentation\" style=\"font-size: 90%; display: inline-block; position: relative;\" tabindex=\"0\"&gt;&lt;svg aria-hidden=\"true\" focusable=\"false\" height=\"1.509ex\" role=\"img\" style=\"vertical-align: -0.","PeriodicalId":238,"journal":{"name":"Acta Materialia","volume":"18 1","pages":""},"PeriodicalIF":9.4,"publicationDate":"2025-09-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145072285","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":"Point defect design in (Ba,Sr)TiO3—An insight on agglomeration","authors":"Sheng-Han Teng ,&nbsp;Anna Grünebohm","doi":"10.1016/j.actamat.2025.121504","DOIUrl":"10.1016/j.actamat.2025.121504","url":null,"abstract":"<div><div>Functional properties of ferroelectrics and their changes with time depend crucially on the defect structure. In particular, point defects and bias fields induced by defect dipoles modify the field hysteresis and play an important role in fatigue and aging. However, a full understanding on how order, agglomeration and strength of defect dipoles affect phase stability and functional properties is still lacking. To close these gaps in knowledge, we screen these parameters by <em>ab initio</em> based molecular dynamics simulations with the effective Hamiltonian method for the prototypical ferroelectric material (Ba,Sr)TiO<span><math><msub><mrow></mrow><mrow><mn>3</mn></mrow></msub></math></span>. Our findings suggest that the <em>active surface area</em> of the defects, rather than the defect concentration is the decisive factor. For a fixed defect concentration, clustering reduces the <em>active surface area</em> and thus the defect-induced changes of phase stability and field hysteresis. Particularly planar agglomerates of defects appear as promising route for the material design as their impact on the field hysteresis can be controlled by the field direction and as their impact on the phase stability shows a cross-over with the strength of the defect dipoles. For this agglomeration, we show that the recoverable stored energy can outperform the response of pristine (Ba,Sr)TiO<span><math><msub><mrow></mrow><mrow><mn>3</mn></mrow></msub></math></span> even in its paraelectric phase due to a pinched double-loop field hysteresis.</div></div>","PeriodicalId":238,"journal":{"name":"Acta Materialia","volume":"301 ","pages":"Article 121504"},"PeriodicalIF":9.3,"publicationDate":"2025-09-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145067830","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":"Texture evolution in polycrystalline FeMnAlNi shape-memory alloy sheets","authors":"Kerui Song ,&nbsp;Sheng Xu ,&nbsp;Ryosuke Kainuma ,&nbsp;Toshihiro Omori","doi":"10.1016/j.actamat.2025.121554","DOIUrl":"10.1016/j.actamat.2025.121554","url":null,"abstract":"<div><div>For polycrystalline Fe-based shape-memory alloys, the crystallographic texture is critical for relieving grain boundary constraints and optimizing mechanical properties, such as superelasticity and ductility. In this study, the texture evolution in a polycrystalline FeMnAlNi alloy subjected to cold rolling, primary recrystallization, and secondary recrystallization was systematically investigated using electron backscatter diffraction. Starting from a body-centered cubic (BCC) + face-centered cubic (FCC) two-phase microstructure, the 94.1 % cold-rolled sample exhibited a predominantly FCC phase with a strong Brass texture component accompanied by a minor volume fraction of the BCC phase. After primary recrystallization annealing, the orientations of the grown BCC grains were governed by the Kurdjumov–Sachs orientation relationship with the adjacent FCC grains. These BCC grains predominantly exhibited {433}&lt;337&gt; and {100}&lt;011&gt; orientations. When the temperature exceeded ∼1120 °C, abnormal grain growth of a small fraction of {211}&lt;011&gt;-oriented BCC grains occurred concurrently with the dissolution of the FCC phase. Furthermore, the colonial structure and Σ9 boundary likely contributed to the exceptional grain boundary migration rate, ultimately yielding a pronounced {211}&lt;011&gt; texture in the BCC single-phase microstructure.</div></div>","PeriodicalId":238,"journal":{"name":"Acta Materialia","volume":"301 ","pages":"Article 121554"},"PeriodicalIF":9.3,"publicationDate":"2025-09-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145072283","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 transformation in Ce-Doped zirconia single and oligo-crystals: In-situ micro-compression with electron back-scattered diffraction analysis","authors":"M.D. Magalhães ,&nbsp;S. Kalácska ,&nbsp;S. Comby-Dassonneville ,&nbsp;T. Douillard ,&nbsp;G. Huynh ,&nbsp;H. Reveron ,&nbsp;S. Meille ,&nbsp;T.W. Cornelius ,&nbsp;G. Kermouche ,&nbsp;O. Thomas ,&nbsp;J. Chevalier","doi":"10.1016/j.actamat.2025.121553","DOIUrl":"10.1016/j.actamat.2025.121553","url":null,"abstract":"<div><div>This study examines for the first time phase transformation of single and oligo-crystalline tetragonal zirconia micropillars under <em>in-situ</em> compression with Electron Back-Scattered Diffraction (EBSD). The tetragonal-to-monoclinic (<em>t-m</em>) phase transformation in ceria-doped zirconia pillars is initiated when a critical stress threshold is reached and propagates along individual grains with increasing stress. Grain boundaries, triple junctions, and small processing-related pores, which lead to localized stress concentrations, facilitate the transformation by lowering the effective applied critical stress. Our findings also align well with the predictions of the crystallographic theory and extend observations from prior studies on single-crystal systems, thereby providing a clearer understanding of the sequences of stress-induced phase transformation in oligo-crystalline tetragonal zirconia.</div></div>","PeriodicalId":238,"journal":{"name":"Acta Materialia","volume":"301 ","pages":"Article 121553"},"PeriodicalIF":9.3,"publicationDate":"2025-09-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145068051","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}