Pub Date : 2026-01-14DOI: 10.1016/j.mtla.2026.102661
A. Stubbers , E. Solano-Castrejon , B. Swartley , S. Durkee , E. Schwind , A. Ramírez-Acosta , C.R. Weinberger , O.A. Graeve , M.S. García-Vázquez , G.B. Thompson
Serial sectioning enables 3D reconstruction of microstructures, providing detailed characterization and insight into processing–structure–property relationships. However, collecting serial section data is time-consuming because many images are required to create reliable reconstructions. In this paper, we investigate the application of machine learning to interpolate intermediate images between reference images, enabling larger cut depths and reducing the total number of collected images. Thus, increasing serial sectioning efficiency and accessibility. Specifically, we describe serial sectioning and a convolutional neural network (CNN) approach with fine-tuning to interpolate crack networks in ζ-Ta4C3-x. The accuracy of CNN-assisted serial sectioning datasets was evaluated using direct image comparison and crack surface area. Two crack types (planar and kinking) were identified to assess the specific capacity of the CNN to recreate complex ζ-Ta4C3-x cracking environments. Results showed that the CNN-generated whole image error was 0.98% with a window size of 129 images and a corresponding cut depth of 3.84 µm. These findings suggest that the serial sectioning time could be reduced by up to 96% with minimal loss in accuracy. By significantly decreasing data collection time, this approach makes serial sectioning more practical for materials characterization and enhances our ability to study material structure and performance at the microscale.
{"title":"Machine learning assisted serial sectioning to enable rapid 3D crack network reconstruction","authors":"A. Stubbers , E. Solano-Castrejon , B. Swartley , S. Durkee , E. Schwind , A. Ramírez-Acosta , C.R. Weinberger , O.A. Graeve , M.S. García-Vázquez , G.B. Thompson","doi":"10.1016/j.mtla.2026.102661","DOIUrl":"10.1016/j.mtla.2026.102661","url":null,"abstract":"<div><div>Serial sectioning enables 3D reconstruction of microstructures, providing detailed characterization and insight into processing–structure–property relationships. However, collecting serial section data is time-consuming because many images are required to create reliable reconstructions. In this paper, we investigate the application of machine learning to interpolate intermediate images between reference images, enabling larger cut depths and reducing the total number of collected images. Thus, increasing serial sectioning efficiency and accessibility. Specifically, we describe serial sectioning and a convolutional neural network (CNN) approach with fine-tuning to interpolate crack networks in ζ-Ta<sub>4</sub>C<sub>3-</sub><em><sub>x</sub></em>. The accuracy of CNN-assisted serial sectioning datasets was evaluated using direct image comparison and crack surface area. Two crack types (planar and kinking) were identified to assess the specific capacity of the CNN to recreate complex ζ-Ta<sub>4</sub>C<sub>3-</sub><em><sub>x</sub></em> cracking environments. Results showed that the CNN-generated whole image error was 0.98% with a window size of 129 images and a corresponding cut depth of 3.84 µm. These findings suggest that the serial sectioning time could be reduced by up to 96% with minimal loss in accuracy. By significantly decreasing data collection time, this approach makes serial sectioning more practical for materials characterization and enhances our ability to study material structure and performance at the microscale.</div></div>","PeriodicalId":47623,"journal":{"name":"Materialia","volume":"45 ","pages":"Article 102661"},"PeriodicalIF":2.9,"publicationDate":"2026-01-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146038173","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}
Oxides in atomized 316L stainless steel powders critically affect their behavior during additive manufacturing and sintering processes, as well as the impact toughness of the final components. This study characterizes eight 316L powders produced by different atomization techniques, with varying particle size distributions and oxygen levels. X-ray photoelectron spectroscopy (XPS), Scanning Electron Microscopy (SEM), X-ray diffraction (XRD) and Raman spectroscopy were used to analyze the composition and morphology of the oxides. The results show that the particle surface oxides were primarily composed of (Cr₂O₃) and iron oxides, with nodules of manganese and silicon oxides observed in some samples. No silicon oxides were detected on the particles surface with oxygen levels around 200 ppm. In addition to surface oxides, internal oxide nanoparticles were also identified. The study demonstrates that the oxidation state is strongly influenced by the oxygen content, atomization process, and raw material properties, offering valuable insights for optimizing powder performance in metallurgical applications.
{"title":"Characterization of oxides on atomized 316L stainless steel powders","authors":"Salima Benrabah , Yoann Danlos , Christophe Verdy , Olivier Heintz , Régis Parvaud , Cécile Langlade","doi":"10.1016/j.mtla.2026.102659","DOIUrl":"10.1016/j.mtla.2026.102659","url":null,"abstract":"<div><div>Oxides in atomized 316L stainless steel powders critically affect their behavior during additive manufacturing and sintering processes, as well as the impact toughness of the final components. This study characterizes eight 316L powders produced by different atomization techniques, with varying particle size distributions and oxygen levels. X-ray photoelectron spectroscopy (XPS), Scanning Electron Microscopy (SEM), X-ray diffraction (XRD) and Raman spectroscopy were used to analyze the composition and morphology of the oxides. The results show that the particle surface oxides were primarily composed of (Cr₂O₃) and iron oxides, with nodules of manganese and silicon oxides observed in some samples. No silicon oxides were detected on the particles surface with oxygen levels around 200 ppm. In addition to surface oxides, internal oxide nanoparticles were also identified. The study demonstrates that the oxidation state is strongly influenced by the oxygen content, atomization process, and raw material properties, offering valuable insights for optimizing powder performance in metallurgical applications.</div></div>","PeriodicalId":47623,"journal":{"name":"Materialia","volume":"45 ","pages":"Article 102659"},"PeriodicalIF":2.9,"publicationDate":"2026-01-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146077436","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}
Pub Date : 2026-01-14DOI: 10.1016/j.mtla.2026.102664
Gabriel Peinado , Daniela P.M. Fonseca , Naga V.V. Mogili , Carlos Ospina , Antonio J. Ramirez , Carlos A.R.P. Baptista , Julian Avila
Maraging steel with 18 wt.% Ni (Mar18Ni) has attracted growing interest for additive manufacturing (AM), particularly through powder bed fusion with a laser beam (PBF-LB), owing to its high strength and heat-treatability. However, the microstructural characteristics introduced by PBF-LB can significantly influence phase transformation pathways during post-processing. While conventionally processed maraging steels have been extensively studied, the precipitation behavior and austenite reversion kinetics in AM-produced Mar18Ni steel remain insufficiently understood. This study investigates the phase transformations in PBF-LB Mar18Ni steel using in-situ transmission electron microscopy (TEM). Samples were subjected to isothermal aging at 480 °C and austenite reversion heat treatments at 650 and 670 °C. The evolution of intermetallic precipitates and the nucleation and morphological development of austenite were systematically characterized. The first precipitation sequence involved Fe2(Mo,Ti) and Ni3Mo after ∼1 h at 480 °C, followed by Ni3Ti formation after a crystallographic rearrangement between martensite and austenite. Unlike the conventionally processed alloy, Ni3Mo forms prior to Ni3Ti in this PBF-LB steel. During aging, precipitation initially competes with austenite reversion as Fe, Ni, and Ti are consumed from the matrix, reducing austenite stability. With prolonged exposure, however, austenite persists and coarsens. At 650 °C, twinning-mediated reversion begins after ∼12 min, whereas at 670 °C, reversion proceeds entirely via the Kurdjumov-Sachs orientation relationship. Al-Ti-rich nano-oxides act as preferential heterogeneous nucleation sites for austenite, promoting reversion but limiting further precipitation. Overall, the results reveal a thermokinetic balance between precipitation and reversion in PBF-LB Mar18Ni steel, providing mechanistic insight into its microstructural evolution.
{"title":"In-situ observation of precipitation and austenite reversion in additively manufactured 18 wt. % Ni maraging steel","authors":"Gabriel Peinado , Daniela P.M. Fonseca , Naga V.V. Mogili , Carlos Ospina , Antonio J. Ramirez , Carlos A.R.P. Baptista , Julian Avila","doi":"10.1016/j.mtla.2026.102664","DOIUrl":"10.1016/j.mtla.2026.102664","url":null,"abstract":"<div><div>Maraging steel with 18 wt.% Ni (Mar18Ni) has attracted growing interest for additive manufacturing (AM), particularly through powder bed fusion with a laser beam (PBF-LB), owing to its high strength and heat-treatability. However, the microstructural characteristics introduced by PBF-LB can significantly influence phase transformation pathways during post-processing. While conventionally processed maraging steels have been extensively studied, the precipitation behavior and austenite reversion kinetics in AM-produced Mar18Ni steel remain insufficiently understood. This study investigates the phase transformations in PBF-LB Mar18Ni steel using in-situ transmission electron microscopy (TEM). Samples were subjected to isothermal aging at 480 °C and austenite reversion heat treatments at 650 and 670 °C. The evolution of intermetallic precipitates and the nucleation and morphological development of austenite were systematically characterized. The first precipitation sequence involved Fe<sub>2</sub>(Mo,Ti) and Ni<sub>3</sub>Mo after ∼1 h at 480 °C, followed by Ni<sub>3</sub>Ti formation after a crystallographic rearrangement between martensite and austenite. Unlike the conventionally processed alloy, Ni<sub>3</sub>Mo forms prior to Ni<sub>3</sub>Ti in this PBF-LB steel. During aging, precipitation initially competes with austenite reversion as Fe, Ni, and Ti are consumed from the matrix, reducing austenite stability. With prolonged exposure, however, austenite persists and coarsens. At 650 °C, twinning-mediated reversion begins after ∼12 min, whereas at 670 °C, reversion proceeds entirely via the Kurdjumov-Sachs orientation relationship. Al-Ti-rich nano-oxides act as preferential heterogeneous nucleation sites for austenite, promoting reversion but limiting further precipitation. Overall, the results reveal a thermokinetic balance between precipitation and reversion in PBF-LB Mar18Ni steel, providing mechanistic insight into its microstructural evolution.</div></div>","PeriodicalId":47623,"journal":{"name":"Materialia","volume":"45 ","pages":"Article 102664"},"PeriodicalIF":2.9,"publicationDate":"2026-01-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146037649","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}
Pub Date : 2026-01-14DOI: 10.1016/j.mtla.2026.102665
Olga Russkikh , Anastasia Permyakova , Elena Filonova , Evgenii Velichko , Alexander Ostroushko
Perovskite nanomaterials based on LaMnO3+δ doped with alkali metals are effective and inexpensive catalysts for the oxidation of soot, a byproduct of the incomplete combustion of fuels or organic compounds. Present study examines the synthesis characteristics and properties of the La0.9A0.1MnO3+δ (A=Li, Na, K, Rb, Cs) catalysts for soot oxidation with atmospheric oxygen as a function of the crystallographic radii and electronegativity of the alkali dopants in the perovskite A-site. Correlations are established between the combustion temperature of the initial precursors, the intensity of the electrical charges generated in the precursors during combustion, the specific surface area of the resulting complex oxides, and the activation energy of the catalytic oxidation of carbon black. The relationship between the above parameters and the ionic radius and electronegativity of the dopants is also considered. It is shown that in the presence of the LaMnO3+δ-based catalysts: 1) the concentration of released carbon(II) oxide is reduced by >50 times, 2) soot is more completely oxidized to CO2, and 3) the degree of soot conversion increases when the catalyst is applied to the nickel foam support.
{"title":"Synthesis, structure and catalytic activity features of alkali-substituted nanostructured lanthanum manganites","authors":"Olga Russkikh , Anastasia Permyakova , Elena Filonova , Evgenii Velichko , Alexander Ostroushko","doi":"10.1016/j.mtla.2026.102665","DOIUrl":"10.1016/j.mtla.2026.102665","url":null,"abstract":"<div><div>Perovskite nanomaterials based on LaMnO<sub>3+δ</sub> doped with alkali metals are effective and inexpensive catalysts for the oxidation of soot, a byproduct of the incomplete combustion of fuels or organic compounds. Present study examines the synthesis characteristics and properties of the La<sub>0.9</sub>A<sub>0.1</sub>MnO<sub>3+δ</sub> (<em>A</em>=Li, Na, K, Rb, Cs) catalysts for soot oxidation with atmospheric oxygen as a function of the crystallographic radii and electronegativity of the alkali dopants in the perovskite A-site. Correlations are established between the combustion temperature of the initial precursors, the intensity of the electrical charges generated in the precursors during combustion, the specific surface area of the resulting complex oxides, and the activation energy of the catalytic oxidation of carbon black. The relationship between the above parameters and the ionic radius and electronegativity of the dopants is also considered. It is shown that in the presence of the LaMnO<sub>3+δ</sub>-based catalysts: 1) the concentration of released carbon(II) oxide is reduced by >50 times, 2) soot is more completely oxidized to CO<sub>2</sub>, and 3) the degree of soot conversion increases when the catalyst is applied to the nickel foam support.</div></div>","PeriodicalId":47623,"journal":{"name":"Materialia","volume":"45 ","pages":"Article 102665"},"PeriodicalIF":2.9,"publicationDate":"2026-01-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146038172","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}
Inspired by the observed similarity in the phase constitution and grain scale of powders and laser powder bed fusion (l-PBF) builds, mechanical properties of powder are proposed to reflect the intrinsic mechanical strength of alloy systems. In this study, we propose a combined experimental–numerical method that integrates finite element method (FEM) simulations with particle compression tests to demonstrate this feasibility. Individual 316 L stainless-steel particles were compressed to produce reproducible force–displacement curves. FEM simulations employing the Voce hardening law revealed that the compressive response is sensitive to plastic parameters but largely insensitive to elastic properties. By iteratively fitting the simulations to the experimental data, we successfully determined the true stress–strain relationship of the powders. The validity of the approach was further confirmed by accurately predicting the compression behavior of 316 L particles with different diameters. This study provides a rapid, reliable, and cost-effective tool for powder characterization, enabling alloy screening and composition optimization in l-PBF applications.
{"title":"Mechanical property evaluation of 316 L micro-powders via particle compression tests and finite element method simulation","authors":"Tao Zhang , Shoma Sekita , Weiwei Zhou, Zhenxing Zhou, Mingqi Dong, Naoyuki Nomura","doi":"10.1016/j.mtla.2026.102660","DOIUrl":"10.1016/j.mtla.2026.102660","url":null,"abstract":"<div><div>Inspired by the observed similarity in the phase constitution and grain scale of powders and laser powder bed fusion (<span><span>l</span></span>-PBF) builds, mechanical properties of powder are proposed to reflect the intrinsic mechanical strength of alloy systems. In this study, we propose a combined experimental–numerical method that integrates finite element method (FEM) simulations with particle compression tests to demonstrate this feasibility. Individual 316 L stainless-steel particles were compressed to produce reproducible force–displacement curves. FEM simulations employing the Voce hardening law revealed that the compressive response is sensitive to plastic parameters but largely insensitive to elastic properties. By iteratively fitting the simulations to the experimental data, we successfully determined the true stress–strain relationship of the powders. The validity of the approach was further confirmed by accurately predicting the compression behavior of 316 L particles with different diameters. This study provides a rapid, reliable, and cost-effective tool for powder characterization, enabling alloy screening and composition optimization in <span>l</span>-PBF applications.</div></div>","PeriodicalId":47623,"journal":{"name":"Materialia","volume":"45 ","pages":"Article 102660"},"PeriodicalIF":2.9,"publicationDate":"2026-01-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146077432","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}
Pub Date : 2026-01-13DOI: 10.1016/j.mtla.2026.102662
Anyong Lu , Xiaoxun Zhang , Fang Ma , Shupeng Guo , Yuangyou Huang
The generation of grain boundary images for metallic materials in additive manufacturing (AM) remains underdeveloped, largely hindered by challenges in multi-source data fusion, grain boundary discontinuity, and inadequate modelling of process–structure relationships. To address these issues, this study proposes a conditional diffusion model (GCSA-CDDPM) enhanced by a global channel–spatial attention mechanism, validated on SLM-processed 316 L stainless steel. The proposed approach comprises three core strategies: (1) designing a unified pipeline for processing heterogeneous grain boundary images, enabling the construction of a high-quality, multi-scale, cross-literature dataset; (2) Putting forward the GCSA module with the process parameter embedding structure to enhance the image structure modelling and generation modulation capability; and (3) introducing a hierarchical breakpoint repair strategy to enhance boundary continuity. Experimental results demonstrate that GCSA-CDDPM surpasses baseline models in structural fidelity, scale conformity, and parameter responsiveness. It achieves the best performance in FID (33.04), grain size error (7.07%), and matching accuracy (92.93%), while producing visually superior images in terms of boundary integrity, noise suppression, and pattern stability. In addition, our findings confirm the model’s ability to capture implicit mappings across process parameters, microstructural morphology, and grain size evolution. The framework enables high-fidelity grain boundary generation with explicit process-structure mapping, providing a digital tool for accelerating alloy design and quality control in SLM-based manufacturing.
{"title":"GCSA-CDDPM: A novel method for multi-source grain boundary conditional generation in selective laser melting","authors":"Anyong Lu , Xiaoxun Zhang , Fang Ma , Shupeng Guo , Yuangyou Huang","doi":"10.1016/j.mtla.2026.102662","DOIUrl":"10.1016/j.mtla.2026.102662","url":null,"abstract":"<div><div>The generation of grain boundary images for metallic materials in additive manufacturing (AM) remains underdeveloped, largely hindered by challenges in multi-source data fusion, grain boundary discontinuity, and inadequate modelling of process–structure relationships. To address these issues, this study proposes a conditional diffusion model (GCSA-CDDPM) enhanced by a global channel–spatial attention mechanism, validated on SLM-processed 316 L stainless steel. The proposed approach comprises three core strategies: (1) designing a unified pipeline for processing heterogeneous grain boundary images, enabling the construction of a high-quality, multi-scale, cross-literature dataset; (2) Putting forward the GCSA module with the process parameter embedding structure to enhance the image structure modelling and generation modulation capability; and (3) introducing a hierarchical breakpoint repair strategy to enhance boundary continuity. Experimental results demonstrate that GCSA-CDDPM surpasses baseline models in structural fidelity, scale conformity, and parameter responsiveness. It achieves the best performance in FID (33.04), grain size error (7.07%), and matching accuracy (92.93%), while producing visually superior images in terms of boundary integrity, noise suppression, and pattern stability. In addition, our findings confirm the model’s ability to capture implicit mappings across process parameters, microstructural morphology, and grain size evolution. The framework enables high-fidelity grain boundary generation with explicit process-structure mapping, providing a digital tool for accelerating alloy design and quality control in SLM-based manufacturing.</div></div>","PeriodicalId":47623,"journal":{"name":"Materialia","volume":"45 ","pages":"Article 102662"},"PeriodicalIF":2.9,"publicationDate":"2026-01-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146037640","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}
Pub Date : 2026-01-12DOI: 10.1016/j.mtla.2026.102657
Jijo Christudasjustus , Kayla Yano , Minju Choi , Mark Bowden , Tanvi Ajantiwalay , Vaithiyalingam Shutthanandan , Danny J. Edwards , Peter Hosemann , Daniel Schreiber , Tiffany C. Kaspar
Irradiation-induced damage in fusion and fission environments drives complex microstructural changes in structural materials, critically influencing their performance under extreme conditions. Our approach to investigate irradiation-induced microstructural evolution employs a well-defined material structure that allows for a precise assessment of He-induced bubbles and defects. In this study, a 100 nm Fe-8Cr epitaxial film was synthesized on MgO (001) substrate using molecular beam epitaxy, resulting in a grain boundary-free microstructure. The Fe-8Cr alloy film was subsequently irradiated at room temperature with 30 keV He+ at fluences of 1.7 × 1016 and 1.7 × 1017 ions/cm2, corresponding to peak-damages of 0.5 and 5 displacements per atom (dpa), respectively. Cross-sectional transmission electron microscopy revealed swelling of 2.7% for 0.5 dpa and 8.1% for 5 dpa. The defect morphology evolved from isolated dislocation loops primarily oriented along <111> at low fluence to complex dislocation structures at high fluence. Notably, smaller bubbles with low number density were observed at lower fluence, whereas larger bubbles with higher number density developed at higher fluence, coinciding with the formation of an extensive dislocation network. These results provide fundamental insights into the dose-dependent microstructural evolution of Fe-8Cr alloys under irradiation, offering a foundation for understanding defect interactions in model ferritic systems.
{"title":"Dose-dependent evolution of dislocation structures and bubble formation in He irradiated Fe-Cr epitaxial film","authors":"Jijo Christudasjustus , Kayla Yano , Minju Choi , Mark Bowden , Tanvi Ajantiwalay , Vaithiyalingam Shutthanandan , Danny J. Edwards , Peter Hosemann , Daniel Schreiber , Tiffany C. Kaspar","doi":"10.1016/j.mtla.2026.102657","DOIUrl":"10.1016/j.mtla.2026.102657","url":null,"abstract":"<div><div>Irradiation-induced damage in fusion and fission environments drives complex microstructural changes in structural materials, critically influencing their performance under extreme conditions. Our approach to investigate irradiation-induced microstructural evolution employs a well-defined material structure that allows for a precise assessment of He-induced bubbles and defects. In this study, a 100 nm Fe-8Cr epitaxial film was synthesized on MgO (001) substrate using molecular beam epitaxy, resulting in a grain boundary-free microstructure. The Fe-8Cr alloy film was subsequently irradiated at room temperature with 30 keV He<sup>+</sup> at fluences of 1.7 × 10<sup>16</sup> and 1.7 × 10<sup>17</sup> ions/cm<sup>2</sup>, corresponding to peak-damages of 0.5 and 5 displacements per atom (dpa), respectively. Cross-sectional transmission electron microscopy revealed swelling of 2.7% for 0.5 dpa and 8.1% for 5 dpa. The defect morphology evolved from isolated dislocation loops primarily oriented along <111> at low fluence to complex dislocation structures at high fluence. Notably, smaller bubbles with low number density were observed at lower fluence, whereas larger bubbles with higher number density developed at higher fluence, coinciding with the formation of an extensive dislocation network. These results provide fundamental insights into the dose-dependent microstructural evolution of Fe-8Cr alloys under irradiation, offering a foundation for understanding defect interactions in model ferritic systems.</div></div>","PeriodicalId":47623,"journal":{"name":"Materialia","volume":"45 ","pages":"Article 102657"},"PeriodicalIF":2.9,"publicationDate":"2026-01-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145977820","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}
Pub Date : 2026-01-09DOI: 10.1016/j.mtla.2026.102656
JiaLan Ma , YaChao Wang , JiangPing Zhao , HongGang Yang
Chinese fir, commonly used in ancient Chinese architecture, is prone to aging due to prolonged exposure to environmental factors such as UV radiation, temperature fluctuations, and salt spray. This aging process not only alters its microstructure but also significantly weakens its fire resistance, potentially compromising the safety of cultural heritage. To investigate the specific impact of environmental aging on the deterioration of fire resistance in Chinese fir, accelerated aging experiments involving UV aging, high-low temperature cycling, and salt spray erosion are conducted. The results indicate that UV radiation induces lignin degradation in the wood, resulting in an increased heat release rate (HRR) peak to 171 kW/m2. High-low temperature cycling results in the formation of microcracks in the wood, causing the peak smoke temperature to reach 88.6 kW/m2. During salt spray erosion, the catalytic effect of Cl- promotes polysaccharide hydrolysis, which facilitates the formation of dense carbon, reducing the HRR peak to 112 kW/m2. Additionally, the three-level correlation model is established to link environmental stresses, microscopic damage, and combustion reactions. This model reveals the cross-scale causal chain of Chinese Fir, from macro-environmental factors to microscopic damage, and finally to its combustion behavior. This analysis provides an in-depth examination of how various environmental factors influence the fire resistance properties of wood by altering its microstructure, offering a theoretical framework for investigating the aging process of wood materials and enhancing fire resistance performance. It is especially applicable to the preservation and safety assessment of ancient architecture's wooden materials.
{"title":"Mechanisms of fire resistance deterioration in chinese fir induced by environmental aging","authors":"JiaLan Ma , YaChao Wang , JiangPing Zhao , HongGang Yang","doi":"10.1016/j.mtla.2026.102656","DOIUrl":"10.1016/j.mtla.2026.102656","url":null,"abstract":"<div><div>Chinese fir, commonly used in ancient Chinese architecture, is prone to aging due to prolonged exposure to environmental factors such as UV radiation, temperature fluctuations, and salt spray. This aging process not only alters its microstructure but also significantly weakens its fire resistance, potentially compromising the safety of cultural heritage. To investigate the specific impact of environmental aging on the deterioration of fire resistance in Chinese fir, accelerated aging experiments involving UV aging, high-low temperature cycling, and salt spray erosion are conducted. The results indicate that UV radiation induces lignin degradation in the wood, resulting in an increased heat release rate (HRR) peak to 171 kW/m<sup>2</sup>. High-low temperature cycling results in the formation of microcracks in the wood, causing the peak smoke temperature to reach 88.6 kW/m<sup>2</sup>. During salt spray erosion, the catalytic effect of Cl<sup>-</sup> promotes polysaccharide hydrolysis, which facilitates the formation of dense carbon, reducing the HRR peak to 112 kW/m<sup>2</sup>. Additionally, the three-level correlation model is established to link environmental stresses, microscopic damage, and combustion reactions. This model reveals the cross-scale causal chain of Chinese Fir, from macro-environmental factors to microscopic damage, and finally to its combustion behavior. This analysis provides an in-depth examination of how various environmental factors influence the fire resistance properties of wood by altering its microstructure, offering a theoretical framework for investigating the aging process of wood materials and enhancing fire resistance performance. It is especially applicable to the preservation and safety assessment of ancient architecture's wooden materials.</div></div>","PeriodicalId":47623,"journal":{"name":"Materialia","volume":"45 ","pages":"Article 102656"},"PeriodicalIF":2.9,"publicationDate":"2026-01-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145977824","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}
Pub Date : 2026-01-07DOI: 10.1016/j.mtla.2026.102654
Jing Xing, Yilong Ouyang, Haitao Ma, Ning Zhao
Interfacial spallation of intermetallic compounds (IMCs) in Ni-based diffusion barrier layers is a critical reliability concern in lead-free solder joints, yet its governing mechanism remains controversial. In this study, electroless Ni–P diffusion barriers with distinct smooth and cellular surface morphologies were fabricated and reacted with SAC305 solder to elucidate the role of barrier morphology in IMC spallation behavior and joint reliability. Wetting angles were measured to evaluate interfacial energy, while barrier layer consumption kinetics were analyzed to assess atomic diffusion behavior across the interface. Although similar interfacial reaction products form in both systems, pronounced IMC spallation is observed only at cellular Ni–P/SAC305 interfaces. Smooth Ni–P coatings exhibit a lower interfacial energy and a significantly reduced interfacial reaction rate (k = 0.46) compared with cellular Ni–P coatings (k = 0.97), effectively suppressing IMC growth, coarsening, and subsequent detachment. In contrast, the protruding cellular morphology and abundant diffusion pathways in cellular Ni–P promote accelerated atomic diffusion, leading to enhanced IMC maturation and severe spallation. Mechanical shear testing further confirms that smooth Ni–P/SAC305 joints achieve a substantially higher average shear strength (34.32 MPa) than their cellular counterparts (20.24 MPa). These results demonstrate that IMC spallation is governed by a synergistic interplay between interfacial energy and diffusion kinetics. Establishing a thermodynamic–kinetic framework provides new insight into interfacial stability at Ni–P/solder interfaces and identifies surface morphology tailoring of Ni–P diffusion barriers as an effective strategy to mitigate IMC spallation and enhance solder joint reliability.
{"title":"Suppression of interfacial IMCs spallation in Ni-P/SAC305 joints via barrier layer morphology control","authors":"Jing Xing, Yilong Ouyang, Haitao Ma, Ning Zhao","doi":"10.1016/j.mtla.2026.102654","DOIUrl":"10.1016/j.mtla.2026.102654","url":null,"abstract":"<div><div>Interfacial spallation of intermetallic compounds (IMCs) in Ni-based diffusion barrier layers is a critical reliability concern in lead-free solder joints, yet its governing mechanism remains controversial. In this study, electroless Ni–P diffusion barriers with distinct smooth and cellular surface morphologies were fabricated and reacted with SAC305 solder to elucidate the role of barrier morphology in IMC spallation behavior and joint reliability. Wetting angles were measured to evaluate interfacial energy, while barrier layer consumption kinetics were analyzed to assess atomic diffusion behavior across the interface. Although similar interfacial reaction products form in both systems, pronounced IMC spallation is observed only at cellular Ni–P/SAC305 interfaces. Smooth Ni–P coatings exhibit a lower interfacial energy and a significantly reduced interfacial reaction rate (<em>k</em> = 0.46) compared with cellular Ni–P coatings (<em>k</em> = 0.97), effectively suppressing IMC growth, coarsening, and subsequent detachment. In contrast, the protruding cellular morphology and abundant diffusion pathways in cellular Ni–P promote accelerated atomic diffusion, leading to enhanced IMC maturation and severe spallation. Mechanical shear testing further confirms that smooth Ni–P/SAC305 joints achieve a substantially higher average shear strength (34.32 MPa) than their cellular counterparts (20.24 MPa). These results demonstrate that IMC spallation is governed by a synergistic interplay between interfacial energy and diffusion kinetics. Establishing a thermodynamic–kinetic framework provides new insight into interfacial stability at Ni–P/solder interfaces and identifies surface morphology tailoring of Ni–P diffusion barriers as an effective strategy to mitigate IMC spallation and enhance solder joint reliability.</div></div>","PeriodicalId":47623,"journal":{"name":"Materialia","volume":"45 ","pages":"Article 102654"},"PeriodicalIF":2.9,"publicationDate":"2026-01-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145939111","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}
Pub Date : 2026-01-06DOI: 10.1016/j.mtla.2026.102653
Mostafa M.A. Mohamed , Mohamed H. Hamza , Laurence A.J. Garvie , M.F. Rabbi , Desireé Cotto-Figueroa , Erik Asphaug , Aditi Chattopadhyay
The mechanical behavior and fracture evolution of the Viñales meteorite were investigated through combined microstructural characterization and quasi-static compression experiments. Elemental mapping and electron imaging reveal a material dominated by a heterogeneous distribution of silicate minerals, with embedded Fe–Ni metal and troilite grains, which, as a whole, is penetrated by pervasive shock-melt veins. Compression tests with digital image correlation show brittle stress–strain responses and highly localized deformation that evolve into complex fracture networks, producing both single and multiple axial splits. X-ray computed tomography shows that cracks preferentially propagate through the brittle phases, i.e., troilite and silicates, whereas the ductile Fe–Ni metal grains deflect or arrest their growth. These results highlight the strong influence of microstructural heterogeneity on fragmentation processes in meteorites. The findings provide new insights into fracture mechanisms in stony astromaterials, with implications for asteroid disruption, regolith formation, and predictive modeling of failure in meteoritic materials.
{"title":"Mechanical and failure behavior of the viñales (L6) ordinary chondrite: linking microstructure to axial splitting fractures","authors":"Mostafa M.A. Mohamed , Mohamed H. Hamza , Laurence A.J. Garvie , M.F. Rabbi , Desireé Cotto-Figueroa , Erik Asphaug , Aditi Chattopadhyay","doi":"10.1016/j.mtla.2026.102653","DOIUrl":"10.1016/j.mtla.2026.102653","url":null,"abstract":"<div><div>The mechanical behavior and fracture evolution of the Viñales meteorite were investigated through combined microstructural characterization and quasi-static compression experiments. Elemental mapping and electron imaging reveal a material dominated by a heterogeneous distribution of silicate minerals, with embedded Fe–Ni metal and troilite grains, which, as a whole, is penetrated by pervasive shock-melt veins. Compression tests with digital image correlation show brittle stress–strain responses and highly localized deformation that evolve into complex fracture networks, producing both single and multiple axial splits. X-ray computed tomography shows that cracks preferentially propagate through the brittle phases, i.e., troilite and silicates, whereas the ductile Fe–Ni metal grains deflect or arrest their growth. These results highlight the strong influence of microstructural heterogeneity on fragmentation processes in meteorites. The findings provide new insights into fracture mechanisms in stony astromaterials, with implications for asteroid disruption, regolith formation, and predictive modeling of failure in meteoritic materials.</div></div>","PeriodicalId":47623,"journal":{"name":"Materialia","volume":"45 ","pages":"Article 102653"},"PeriodicalIF":2.9,"publicationDate":"2026-01-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145977825","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}
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