Materialia最新文献

{"title":"Microstructure-controlled stress evolution during Cu6Sn5 growth in Sn/Cu coatings","authors":"Erik Jacobsson,&nbsp;Håkan Hallberg,&nbsp;Johan Hektor,&nbsp;Matti Ristinmaa","doi":"10.1016/j.mtla.2026.102873","DOIUrl":"10.1016/j.mtla.2026.102873","url":null,"abstract":"<div><div>Growth of the intermetallic compound (IMC) <span><math><mrow><msub><mrow><mtext>Cu</mtext></mrow><mrow><mn>6</mn></mrow></msub><msub><mrow><mtext>Sn</mtext></mrow><mrow><mn>5</mn></mrow></msub></mrow></math></span> in Sn/Cu coatings is a major source of stress evolution and is closely linked to the reliability of electroplated Sn layers, including their susceptibility to whisker formation. Here, we investigate how Sn grain morphology and grain boundary (GB) transport control stress development during diffusion-controlled <span><math><mrow><msub><mrow><mtext>Cu</mtext></mrow><mrow><mn>6</mn></mrow></msub><msub><mrow><mtext>Sn</mtext></mrow><mrow><mn>5</mn></mrow></msub></mrow></math></span> growth. A thermodynamically consistent sharp-interface framework is developed that couples atomic diffusion, elasto-plastic deformation, moving interphase interfaces and GB diffusion and sliding. The model is solved in a finite element setting using the Voronoi implicit interface method to capture evolving <span><math><mrow><msub><mrow><mtext>Cu</mtext></mrow><mrow><mn>6</mn></mrow></msub><msub><mrow><mtext>Sn</mtext></mrow><mrow><mn>5</mn></mrow></msub></mrow></math></span> morphologies. Simulations of Sn coatings on Cu substrates reproduce experimentally observed trends in <span><math><mrow><msub><mrow><mtext>Cu</mtext></mrow><mrow><mn>6</mn></mrow></msub><msub><mrow><mtext>Sn</mtext></mrow><mrow><mn>5</mn></mrow></msub></mrow></math></span> growth and biaxial stress evolution. In columnar Sn microstructures, IMC growth produces a build-up of biaxial compressive stress that saturates at experimentally relevant levels, even without GB creep. In contrast, non-columnar microstructures activate GB diffusion and sliding along inclined boundaries, leading to substantial stress relaxation. The results show that GB diffusion and sliding are orientation-dependent relaxation mechanisms rather than sources of stress generation, providing a mechanistic explanation for the reduced stress levels observed in non-columnar Sn coatings.</div></div>","PeriodicalId":47623,"journal":{"name":"Materialia","volume":"49 ","pages":"Article 102873"},"PeriodicalIF":3.1,"publicationDate":"2026-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148952475","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Tribo-corrosion behavior and mechanism of laser-clad TC4-WC coating: Effect of applied load and potential","authors":"Qinying Wang,&nbsp;Daichen Li,&nbsp;Kang Wang,&nbsp;Yuchen Xi,&nbsp;Xianqin Feng,&nbsp;Lijin Dong,&nbsp;Yangfei Zhang,&nbsp;Shulin Bai","doi":"10.1016/j.mtla.2026.102872","DOIUrl":"10.1016/j.mtla.2026.102872","url":null,"abstract":"<div><div>Applied load and polarization potential are the key factors influence the tribo-corrosion of laser-clad TC4-WC coatings. This study analyzed the microstructure and conducted systematic study of the in-situ electrochemical tribo-corrosion behavior of laser-clad TC4-WC coatings. The coating mainly consists of β-Ti, WC, W₂C, TiC and W, with strong metallurgical bonding between WC particles and the TC4 matrix. As the applied load increases during tribo-corrosion, the corrosion current density (<em>I_corr</em>) of the coating rises and the charge transfer resistance decreases, indicating that the increasing load aggravates the mechanical disruption of the passive film, enhances the tribo-corrosion synergy, and promotes the transition of wear mechanism from abrasive wear to multi-mechanism synergy. As the applied potential increases, the tribo-corrosion rate peaks at 0.20 V, and the tribo-corrosion rate at 1.0 V remains 51.69% higher than that under -0.80 V cathodic protection. This indicates that increasing potential promotes the formation of a lubricious WO₃ film, which reduces material loss but increases wear depth, and shifts the wear mechanism to WO₃-assisted lubrication with micro-cracking.</div><div><strong>Novelty Statement:</strong> The laser-clad TC4-WC coating has been applied to enhance TC4 alloy during serving in marine engineering where the coupled action of wear and corrosion was commonly found. However, the tribo-corrosion behavior of laser-cladded TC4-WC coating under combined load and potential conditions remains poorly understood. This study systematically investigates the in-situ electrochemical behavior and tribo-corrosion mechanisms of the TC4-WC coating under varying applied loads and potentials. The results reveal that increasing applied load raises <em>I_corr</em> and decreases total resistance (<em>R_sum</em>), thereby accelerating the electrochemical corrosion process and enhancing the wear-corrosion synergy. As the applied potential increases, the total material loss rate peaks at 0.20 V under anodic polarization, while cathodic protection at -0.80 V effectively suppresses corrosion. At 1.0 V, a thick WO₃ oxide film forms, which enhances lubricity but increases wear depth. This research has important theoretical value and engineering application significance for optimizing service parameters and extending the service life of TC4-WC coatings in marine environments.</div></div>","PeriodicalId":47623,"journal":{"name":"Materialia","volume":"49 ","pages":"Article 102872"},"PeriodicalIF":3.1,"publicationDate":"2026-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148952401","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Microstructure-controlled stress evolution during Cu6Sn5 growth in Sn/Cu coatings","authors":"Erik Jacobsson,&nbsp;Håkan Hallberg,&nbsp;Johan Hektor,&nbsp;Matti Ristinmaa","doi":"10.1016/j.mtla.2026.102873","DOIUrl":"10.1016/j.mtla.2026.102873","url":null,"abstract":"<div><div>Growth of the intermetallic compound (IMC) <span><math><mrow><msub><mrow><mtext>Cu</mtext></mrow><mrow><mn>6</mn></mrow></msub><msub><mrow><mtext>Sn</mtext></mrow><mrow><mn>5</mn></mrow></msub></mrow></math></span> in Sn/Cu coatings is a major source of stress evolution and is closely linked to the reliability of electroplated Sn layers, including their susceptibility to whisker formation. Here, we investigate how Sn grain morphology and grain boundary (GB) transport control stress development during diffusion-controlled <span><math><mrow><msub><mrow><mtext>Cu</mtext></mrow><mrow><mn>6</mn></mrow></msub><msub><mrow><mtext>Sn</mtext></mrow><mrow><mn>5</mn></mrow></msub></mrow></math></span> growth. A thermodynamically consistent sharp-interface framework is developed that couples atomic diffusion, elasto-plastic deformation, moving interphase interfaces and GB diffusion and sliding. The model is solved in a finite element setting using the Voronoi implicit interface method to capture evolving <span><math><mrow><msub><mrow><mtext>Cu</mtext></mrow><mrow><mn>6</mn></mrow></msub><msub><mrow><mtext>Sn</mtext></mrow><mrow><mn>5</mn></mrow></msub></mrow></math></span> morphologies. Simulations of Sn coatings on Cu substrates reproduce experimentally observed trends in <span><math><mrow><msub><mrow><mtext>Cu</mtext></mrow><mrow><mn>6</mn></mrow></msub><msub><mrow><mtext>Sn</mtext></mrow><mrow><mn>5</mn></mrow></msub></mrow></math></span> growth and biaxial stress evolution. In columnar Sn microstructures, IMC growth produces a build-up of biaxial compressive stress that saturates at experimentally relevant levels, even without GB creep. In contrast, non-columnar microstructures activate GB diffusion and sliding along inclined boundaries, leading to substantial stress relaxation. The results show that GB diffusion and sliding are orientation-dependent relaxation mechanisms rather than sources of stress generation, providing a mechanistic explanation for the reduced stress levels observed in non-columnar Sn coatings.</div></div>","PeriodicalId":47623,"journal":{"name":"Materialia","volume":"49 ","pages":"Article 102873"},"PeriodicalIF":3.1,"publicationDate":"2026-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148952479","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A medium-range interpenetrating icosahedral clustering that influences metallic glass formation and mechanical behavior","authors":"Ning Chen,&nbsp;Shuang Yu,&nbsp;Qian Luo,&nbsp;Xinyue Wang,&nbsp;Xinyue Jiang,&nbsp;Jiakai Hu,&nbsp;Shaozhen Zhang,&nbsp;Dechuan Yu,&nbsp;Zhengwang Zhu","doi":"10.1016/j.mtla.2026.102886","DOIUrl":"10.1016/j.mtla.2026.102886","url":null,"abstract":"<div><div>The glass forming ability (GFA) and mechanical properties of metallic glasses (MGs) depend on atomic structure, yet the role of medium-range order (MRO) connectivity remains unclear. Using molecular dynamics simulations, we investigate the interpenetrating connection of icosahedra (ICOI) in Ni–Zr MGs. ICOI forms aggregates with a truncated power-law size distribution; the radius of gyration clusters Size (<span><math><mrow><msub><mi>R</mi><mi>g</mi></msub><mrow><mo>−</mo><mi>S</mi><mo>)</mo></mrow></mrow></math></span> scaling relation reveals loose chain-like or branched growth with a low fractal dimension (<span><math><mrow><msub><mi>d</mi><mi>f</mi></msub><mo>≈</mo><mn>1.59</mn></mrow></math></span>). We propose the average interpenetrating icosahedral cluster size (AIICS) as an MRO parameter and define the coupling slope <span><math><mi>K</mi></math></span> between AIICS and the ICO population as an empirical descriptor of their co-variation. Combining the frame-averaged IIC size (<span><math><msub><mi>S</mi><mrow><mi>a</mi><mi>v</mi><mi>g</mi></mrow></msub></math></span>) with mean-square displacement analysis establishes a direct mechanistic link between IIC network scale and the suppression of atomic dynamics. The final-state AIICS correlates strongly with predicted GFA metrics in the Ni–Zr system, and extending this framework to ternary Ni–Zr–Ti enables a descriptive comparison based on AIICS and the empirical coupling slope <span><math><mi>K</mi></math></span>; the predictive transferability of this framework remains unestablished. Deformation simulations reveal that large IICs form a rigid skeleton resisting shear, while icosahedra with higher interpenetration degrees (<span><math><mi>N</mi></math></span>) exhibit superior shear resistance. Macroscopically, the yield strength correlates positively with AIICS across both compositional and cooling-rate variations, showing a systematic co-variation between the IIC-based descriptors and the simulated mechanical response across the investigated conditions. Overall, the IIC-based MRO descriptor framework provides a new structural perspective for understanding and predicting both GFA and mechanical performance of metallic glasses.</div></div>","PeriodicalId":47623,"journal":{"name":"Materialia","volume":"49 ","pages":"Article 102886"},"PeriodicalIF":3.1,"publicationDate":"2026-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148952477","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Editors for Materialia","authors":"","doi":"10.1016/S2589-1529(26)00239-5","DOIUrl":"10.1016/S2589-1529(26)00239-5","url":null,"abstract":"","PeriodicalId":47623,"journal":{"name":"Materialia","volume":"49 ","pages":"Article 102889"},"PeriodicalIF":3.1,"publicationDate":"2026-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148952476","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Tribo-corrosion behavior and mechanism of laser-clad TC4-WC coating: Effect of applied load and potential","authors":"Qinying Wang,&nbsp;Daichen Li,&nbsp;Kang Wang,&nbsp;Yuchen Xi,&nbsp;Xianqin Feng,&nbsp;Lijin Dong,&nbsp;Yangfei Zhang,&nbsp;Shulin Bai","doi":"10.1016/j.mtla.2026.102872","DOIUrl":"10.1016/j.mtla.2026.102872","url":null,"abstract":"<div><div>Applied load and polarization potential are the key factors influence the tribo-corrosion of laser-clad TC4-WC coatings. This study analyzed the microstructure and conducted systematic study of the in-situ electrochemical tribo-corrosion behavior of laser-clad TC4-WC coatings. The coating mainly consists of β-Ti, WC, W₂C, TiC and W, with strong metallurgical bonding between WC particles and the TC4 matrix. As the applied load increases during tribo-corrosion, the corrosion current density (<em>I_corr</em>) of the coating rises and the charge transfer resistance decreases, indicating that the increasing load aggravates the mechanical disruption of the passive film, enhances the tribo-corrosion synergy, and promotes the transition of wear mechanism from abrasive wear to multi-mechanism synergy. As the applied potential increases, the tribo-corrosion rate peaks at 0.20 V, and the tribo-corrosion rate at 1.0 V remains 51.69% higher than that under -0.80 V cathodic protection. This indicates that increasing potential promotes the formation of a lubricious WO₃ film, which reduces material loss but increases wear depth, and shifts the wear mechanism to WO₃-assisted lubrication with micro-cracking.</div><div><strong>Novelty Statement:</strong> The laser-clad TC4-WC coating has been applied to enhance TC4 alloy during serving in marine engineering where the coupled action of wear and corrosion was commonly found. However, the tribo-corrosion behavior of laser-cladded TC4-WC coating under combined load and potential conditions remains poorly understood. This study systematically investigates the in-situ electrochemical behavior and tribo-corrosion mechanisms of the TC4-WC coating under varying applied loads and potentials. The results reveal that increasing applied load raises <em>I_corr</em> and decreases total resistance (<em>R_sum</em>), thereby accelerating the electrochemical corrosion process and enhancing the wear-corrosion synergy. As the applied potential increases, the total material loss rate peaks at 0.20 V under anodic polarization, while cathodic protection at -0.80 V effectively suppresses corrosion. At 1.0 V, a thick WO₃ oxide film forms, which enhances lubricity but increases wear depth. This research has important theoretical value and engineering application significance for optimizing service parameters and extending the service life of TC4-WC coatings in marine environments.</div></div>","PeriodicalId":47623,"journal":{"name":"Materialia","volume":"49 ","pages":"Article 102872"},"PeriodicalIF":3.1,"publicationDate":"2026-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148952478","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A medium-range interpenetrating icosahedral clustering that influences metallic glass formation and mechanical behavior","authors":"Ning Chen,&nbsp;Shuang Yu,&nbsp;Qian Luo,&nbsp;Xinyue Wang,&nbsp;Xinyue Jiang,&nbsp;Jiakai Hu,&nbsp;Shaozhen Zhang,&nbsp;Dechuan Yu,&nbsp;Zhengwang Zhu","doi":"10.1016/j.mtla.2026.102886","DOIUrl":"10.1016/j.mtla.2026.102886","url":null,"abstract":"<div><div>The glass forming ability (GFA) and mechanical properties of metallic glasses (MGs) depend on atomic structure, yet the role of medium-range order (MRO) connectivity remains unclear. Using molecular dynamics simulations, we investigate the interpenetrating connection of icosahedra (ICOI) in Ni–Zr MGs. ICOI forms aggregates with a truncated power-law size distribution; the radius of gyration clusters Size (<span><math><mrow><msub><mi>R</mi><mi>g</mi></msub><mrow><mo>−</mo><mi>S</mi><mo>)</mo></mrow></mrow></math></span> scaling relation reveals loose chain-like or branched growth with a low fractal dimension (<span><math><mrow><msub><mi>d</mi><mi>f</mi></msub><mo>≈</mo><mn>1.59</mn></mrow></math></span>). We propose the average interpenetrating icosahedral cluster size (AIICS) as an MRO parameter and define the coupling slope <span><math><mi>K</mi></math></span> between AIICS and the ICO population as an empirical descriptor of their co-variation. Combining the frame-averaged IIC size (<span><math><msub><mi>S</mi><mrow><mi>a</mi><mi>v</mi><mi>g</mi></mrow></msub></math></span>) with mean-square displacement analysis establishes a direct mechanistic link between IIC network scale and the suppression of atomic dynamics. The final-state AIICS correlates strongly with predicted GFA metrics in the Ni–Zr system, and extending this framework to ternary Ni–Zr–Ti enables a descriptive comparison based on AIICS and the empirical coupling slope <span><math><mi>K</mi></math></span>; the predictive transferability of this framework remains unestablished. Deformation simulations reveal that large IICs form a rigid skeleton resisting shear, while icosahedra with higher interpenetration degrees (<span><math><mi>N</mi></math></span>) exhibit superior shear resistance. Macroscopically, the yield strength correlates positively with AIICS across both compositional and cooling-rate variations, showing a systematic co-variation between the IIC-based descriptors and the simulated mechanical response across the investigated conditions. Overall, the IIC-based MRO descriptor framework provides a new structural perspective for understanding and predicting both GFA and mechanical performance of metallic glasses.</div></div>","PeriodicalId":47623,"journal":{"name":"Materialia","volume":"49 ","pages":"Article 102886"},"PeriodicalIF":3.1,"publicationDate":"2026-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148952400","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Editors for Materialia","authors":"","doi":"10.1016/S2589-1529(26)00239-5","DOIUrl":"10.1016/S2589-1529(26)00239-5","url":null,"abstract":"","PeriodicalId":47623,"journal":{"name":"Materialia","volume":"49 ","pages":"Article 102889"},"PeriodicalIF":3.1,"publicationDate":"2026-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148952480","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Synergistic energy absorption in hybrid auxetic sandwich panels: A parametric study of combined positive–negative poisson's ratio cores fabricated via fused deposition modeling","authors":"Mohammad Ali Saeimi Sadigh,&nbsp;Hadi Safi Valilu,&nbsp;Moosa Sajed,&nbsp;Mohammad Reza Adibeig","doi":"10.1016/j.mtla.2026.102833","DOIUrl":"10.1016/j.mtla.2026.102833","url":null,"abstract":"<div><div>This study investigates the design, fabrication, and quasi-static compressive behavior of corrugated sandwich panels with auxetic cores manufactured via fused deposition modeling (FDM) using polylactic acid (PLA). Three core topologies, hexagonal honeycomb (positive Poisson's ratio), re-entrant (negative Poisson's ratio), and hybrid (combining both) were systematically evaluated for energy absorption capacity while maintaining a constant relative density. The hybrid core demonstrated superior performance. When tested as a corrugated sandwich panel (core + corrugated skins), the hybrid configuration achieved a specific energy absorption (SEA) of 7.49 J/g, which exceeded that of the honeycomb sandwich panel (4.82 J/g) and re-entrant sandwich panel (5.35 J/g) by 55% and 40%, respectively. These values refer to the full sandwich panel; the core-only SEA values were lower (1.89–4.70 J/g), as the skins and corrugation geometry contribute additional structural stability and energy dissipation. Taguchi optimization identified the optimal FDM printing parameters as a <span><math><mrow><mo>±</mo><msup><mrow><mn>45</mn></mrow><mo>∘</mo></msup></mrow></math></span> raster angle, a printing speed of 4000 mm/min, and a layer thickness of 0.2 mm to maximize ultimate tensile strength (UTS) and energy absorption per unit volume (EA) in the printed PLA material. Finite element simulations showed strong agreement with experimental results, with force-displacement curve deviations below 10% for the hybrid core, accurately predicting deformation modes and progressive collapse behavior. The unique deformation mechanism of the hybrid core combining progressive collapse from honeycomb regions and inward buckling from re-entrant regions enhances energy dissipation while maintaining structural stability, making it a promising candidate for lightweight quasi-static energy absorption applications.</div></div>","PeriodicalId":47623,"journal":{"name":"Materialia","volume":"48 ","pages":"Article 102833"},"PeriodicalIF":3.1,"publicationDate":"2026-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148641302","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Cobalt enrichment at oxide grain boundaries improves zirconium oxidation resistance","authors":"Haijing Tian,&nbsp;Bowen Shi,&nbsp;Taosha Liang","doi":"10.1016/j.mtla.2026.102854","DOIUrl":"10.1016/j.mtla.2026.102854","url":null,"abstract":"<div><div>We report that pre-oxidation of Zr in Co₃O₄ powder at 900 °C leads to the formation of a highly protective oxide scale, and we investigate the underlying mechanism. Co segregates at ZrO₂ grain boundaries, blocking oxygen diffusion, suppressing microcracks, and homogenizing stress. The scale is severely oxygen-deficient (O/Zr &lt; 2), lowering the average valence of Zr. Consequently, Co acts as a donor, reducing oxygen vacancies, contrary to classical defect chemistry. Co incorporation occurs via displacement reaction at the Zr/Co₃O₄ interface and defect-assisted grain boundary segregation. The Co-treated Zr shows a thinner, crack-free oxide scale with enhanced oxidation resistance. Despite Co’s high neutron absorption limiting nuclear use, this work offers mechanistic insights for designing low-absorption alternatives.</div></div>","PeriodicalId":47623,"journal":{"name":"Materialia","volume":"48 ","pages":"Article 102854"},"PeriodicalIF":3.1,"publicationDate":"2026-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148641142","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}