Pub Date : 2025-12-13DOI: 10.1016/j.mtla.2025.102635
James S.K.L. Gibson , Alex Carruthers , Benjamin R.S. Evans , Jack Haley , Slava Kuksenko , Kay Song , Luke Hewitt , Stephen Jones , Shahin Mehraban , Nicholas Lavery , David Bowden
Reduced activation ferritic-martensitic (RAFM) steels are a recent class of radiation-resistant steels designed for the structural components of power-producing fusion reactors. In this work an advanced (A)RAFM steel has been developed with superior radiation hardening resistance with respect to the EUROFER-97 upon which it was based.
4D-STEM (scanning transmission electron microscopy) has been combined with a novel processing methodology to visualise all the fine MX precipitates that led to this outstanding radiation hardening resistance and determine a precipitate density of 5 × 1022 m-3.
Self-ion irradiation campaigns up to 100 dpa at 350 °C show an increase in hardness of only 35 % at 10 dpa where EUROFER-97 exhibits a near-doubling of its hardness. The initial work hardening response, as determined from spherical nanoindentation, is unchanged between the as-received state and irradiation to 100 dpa, implying that the alloy should retain reasonable ductility under these conditions. Proton irradiations at 250 °C, 350 °C, and 400 °C demonstrate that the low temperature hardening embrittlement threshold of the new steel is largely unaffected, increasing by only ∼50 °C with respect to EUROFER-97.
A refinement of alloy chemistry and a subsequent modification of the thermomechanical treatments to favour MX precipitates is therefore a very promising strategy for the further development of fusion steels.
{"title":"Characterisation of MX precipitate density and irradiation hardening in advanced reduced-activation ferritic-martensitic fusion steels","authors":"James S.K.L. Gibson , Alex Carruthers , Benjamin R.S. Evans , Jack Haley , Slava Kuksenko , Kay Song , Luke Hewitt , Stephen Jones , Shahin Mehraban , Nicholas Lavery , David Bowden","doi":"10.1016/j.mtla.2025.102635","DOIUrl":"10.1016/j.mtla.2025.102635","url":null,"abstract":"<div><div>Reduced activation ferritic-martensitic (RAFM) steels are a recent class of radiation-resistant steels designed for the structural components of power-producing fusion reactors. In this work an advanced (A)RAFM steel has been developed with superior radiation hardening resistance with respect to the EUROFER-97 upon which it was based.</div><div>4D-STEM (scanning transmission electron microscopy) has been combined with a novel processing methodology to visualise all the fine MX precipitates that led to this outstanding radiation hardening resistance and determine a precipitate density of 5 × 10<sup>22</sup> m<sup>-3</sup>.</div><div>Self-ion irradiation campaigns up to 100 dpa at 350 °C show an increase in hardness of only 35 % at 10 dpa where EUROFER-97 exhibits a near-doubling of its hardness. The initial work hardening response, as determined from spherical nanoindentation, is unchanged between the as-received state and irradiation to 100 dpa, implying that the alloy should retain reasonable ductility under these conditions. Proton irradiations at 250 °C, 350 °C, and 400 °C demonstrate that the low temperature hardening embrittlement threshold of the new steel is largely unaffected, increasing by only ∼50 °C with respect to EUROFER-97.</div><div>A refinement of alloy chemistry and a subsequent modification of the thermomechanical treatments to favour MX precipitates is therefore a very promising strategy for the further development of fusion steels.</div></div>","PeriodicalId":47623,"journal":{"name":"Materialia","volume":"45 ","pages":"Article 102635"},"PeriodicalIF":2.9,"publicationDate":"2025-12-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145841450","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 : 2025-12-12DOI: 10.1016/j.mtla.2025.102633
Emily Asenath-Smith , Kiera L. Thompson Towell , Matthew A. Fort, Nicholas P. Wilder
Abundant in cold regions, ice rarely exists as a pure single-phase compound but rather contains insoluble particulates and fibrous matter from the local environment. Such second phase materials can drastically change the formation mechanism, microstructure, and properties of the resulting composite ice. Cellulose nanofibers (CNFs) were investigated for their ability to strengthen ice and studied with optical microscopy, ice fabric analysis, and mechanical property measurements. With increasing concentration, the CNFs bridged across grain boundaries and were distributed throughout grain interiors, forming a percolated network within the ice microstructure. The CNFs in ice were found to modify the ice fabric from an S2 classification to one with an irregular distribution of c-axis for intermediate CNF wt%, and appeared to shift back towards S2 as CNF was increased to 1.0 wt%. The addition of up to 1.0 wt% CNF to ice increased the flexural strength from 3.1 MPa to 5.8 MPa in 3-point bending and from 1.7 MPa to 3.8 MPa in 4-point bending, while increasing the compressive strength from 2.6 MPa to 7.2 MPa. The increase in strength correlated with ductility imparted by the CNFs which thereby increased the apparent toughness by a factor of 2 – 10 compared to pure ice. These insights reveal the mechanistic response of CNFs in ice and open future avenues that utilize ice as a high-performance material for structures in cold regions.
{"title":"Cellulose nanofibers in ice: microstructural effects on mechanical response","authors":"Emily Asenath-Smith , Kiera L. Thompson Towell , Matthew A. Fort, Nicholas P. Wilder","doi":"10.1016/j.mtla.2025.102633","DOIUrl":"10.1016/j.mtla.2025.102633","url":null,"abstract":"<div><div>Abundant in cold regions, ice rarely exists as a pure single-phase compound but rather contains insoluble particulates and fibrous matter from the local environment. Such second phase materials can drastically change the formation mechanism, microstructure, and properties of the resulting composite ice. Cellulose nanofibers (CNFs) were investigated for their ability to strengthen ice and studied with optical microscopy, ice fabric analysis, and mechanical property measurements. With increasing concentration, the CNFs bridged across grain boundaries and were distributed throughout grain interiors, forming a percolated network within the ice microstructure. The CNFs in ice were found to modify the ice fabric from an S2 classification to one with an irregular distribution of c-axis for intermediate CNF wt%, and appeared to shift back towards S2 as CNF was increased to 1.0 wt%. The addition of up to 1.0 wt% CNF to ice increased the flexural strength from 3.1 MPa to 5.8 MPa in 3-point bending and from 1.7 MPa to 3.8 MPa in 4-point bending, while increasing the compressive strength from 2.6 MPa to 7.2 MPa. The increase in strength correlated with ductility imparted by the CNFs which thereby increased the apparent toughness by a factor of 2 – 10 compared to pure ice. These insights reveal the mechanistic response of CNFs in ice and open future avenues that utilize ice as a high-performance material for structures in cold regions.</div></div>","PeriodicalId":47623,"journal":{"name":"Materialia","volume":"45 ","pages":"Article 102633"},"PeriodicalIF":2.9,"publicationDate":"2025-12-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145841449","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 : 2025-12-11DOI: 10.1016/j.mtla.2025.102631
Peng Miao , Tie Liu , Shuoxi Yang , Zhengyang Lu , Weibin Cui , Shuang Yuan , Chao Li , Qiang Wang
High magnetic fields (HMFs) can markedly influence wetting behavior by modifying the solid–liquid interfacial structure. However, their effects on the wettability of systems with different interfacial structures remain unexplored. We investigated the wetting behavior of molten Al on α-Al2O3 with different orientations under HMFs and elucidated the underlying wetting mechanism. The Al/R-plane α-Al2O3 system showed the best wettability, with the contact angle reduced by 49° at 6 T. Structural analyses revealed that HMFs induce ordered Al layers epitaxially grown on the substrate (up to ∼13 layers on the R-plane), driving the interface toward near-coherency and reducing the solid–liquid interfacial energy, thereby significantly enhancing wettability. In addition, orientation-dependent differences in substrate surface structures produce distinct interfacial structures with molten Al, resulting in different wettability. These results highlight a new strategy for tailoring wettability and interfacial properties via magnetic field-substrate orientation coupling.
{"title":"Orientation-dependent wetting behavior of molten Al on α-Al2O3 in high magnetic fields","authors":"Peng Miao , Tie Liu , Shuoxi Yang , Zhengyang Lu , Weibin Cui , Shuang Yuan , Chao Li , Qiang Wang","doi":"10.1016/j.mtla.2025.102631","DOIUrl":"10.1016/j.mtla.2025.102631","url":null,"abstract":"<div><div>High magnetic fields (HMFs) can markedly influence wetting behavior by modifying the solid–liquid interfacial structure. However, their effects on the wettability of systems with different interfacial structures remain unexplored. We investigated the wetting behavior of molten Al on α-Al<sub>2</sub>O<sub>3</sub> with different orientations under HMFs and elucidated the underlying wetting mechanism. The Al/R-plane α-Al<sub>2</sub>O<sub>3</sub> system showed the best wettability, with the contact angle reduced by 49° at 6 T. Structural analyses revealed that HMFs induce ordered Al layers epitaxially grown on the substrate (up to ∼13 layers on the R-plane), driving the interface toward near-coherency and reducing the solid–liquid interfacial energy, thereby significantly enhancing wettability. In addition, orientation-dependent differences in substrate surface structures produce distinct interfacial structures with molten Al, resulting in different wettability. These results highlight a new strategy for tailoring wettability and interfacial properties via magnetic field-substrate orientation coupling.</div></div>","PeriodicalId":47623,"journal":{"name":"Materialia","volume":"45 ","pages":"Article 102631"},"PeriodicalIF":2.9,"publicationDate":"2025-12-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145798377","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 : 2025-12-11DOI: 10.1016/j.mtla.2025.102632
Yun JIANG , Boyang ZHAO , Yuqin LIU
Fluoride is a common additive in the thermal reduction process for metallic magnesium. In the work, aluminum fluoride (AlF3) was used in the process of vacuum aluminothermic reduction of magnesia. The process produced the qualified Mg product. Two effects of AlF3 were reported. First, AlF3 significantly accelerates to generate Mg vapor and magnesium aluminate spinel (MA-spinel). Second, it prevents alumina forming. In the presence of 3 % AlF3, the content of the MA-spinel phase in slags could reach 97 %. The reasons behind are suggested. AlF3 offers F- ions to distort the magnesia lattice throughout entire sample, and to make cations’ detachment and substitution easily to accelerate the generation of Mg vapor and MA-spinel. F- ions also help to avoid the rearrangement of oxygen sublattice in partial sample, which prevents the formation of alumina. The introduction of F- ions could change the activation energy allocation during the phase transformation.
{"title":"Two effects of AlF3 in aluminothermic reduction of magnesia","authors":"Yun JIANG , Boyang ZHAO , Yuqin LIU","doi":"10.1016/j.mtla.2025.102632","DOIUrl":"10.1016/j.mtla.2025.102632","url":null,"abstract":"<div><div>Fluoride is a common additive in the thermal reduction process for metallic magnesium. In the work, aluminum fluoride (AlF<sub>3</sub>) was used in the process of vacuum aluminothermic reduction of magnesia. The process produced the qualified Mg product. Two effects of AlF<sub>3</sub> were reported. First, AlF<sub>3</sub> significantly accelerates to generate Mg vapor and magnesium aluminate spinel (MA-spinel). Second, it prevents alumina forming. In the presence of 3 % AlF<sub>3</sub>, the content of the MA-spinel phase in slags could reach 97 %. The reasons behind are suggested. AlF<sub>3</sub> offers F<sup>-</sup> ions to distort the magnesia lattice throughout entire sample, and to make cations’ detachment and substitution easily to accelerate the generation of Mg vapor and MA-spinel. F<sup>-</sup> ions also help to avoid the rearrangement of oxygen sublattice in partial sample, which prevents the formation of alumina. The introduction of F<sup>-</sup> ions could change the activation energy allocation during the phase transformation.</div></div>","PeriodicalId":47623,"journal":{"name":"Materialia","volume":"45 ","pages":"Article 102632"},"PeriodicalIF":2.9,"publicationDate":"2025-12-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145798381","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 : 2025-12-10DOI: 10.1016/j.mtla.2025.102630
Hasan Al Jame , Jiayun Shao , Jixuan Dong , Pranav Karve , Kyle Mumm , Bryan A. Webler , Anthony D. Rollett , Sankaran Mahadevan , Tao Sun , S. Mohadeseh Taheri-Mousavi
Alloy 718 (UNS N07718) is a widely utilized additively manufacturable superalloy for extreme-temperature applications for its superior mechanical properties. However, laser powder bed fusion of alloy 718 can exhibit yield strength variability of almost 400 MPa. Compositional variation during processing is one of the critical driving factors for such variation. Here, we combined validated calculation of phase diagrams (CALPHAD)-based integrated computational materials engineering (ICME) techniques to simulate microstructural features in as-built and fully-aged equilibrium conditions at 650 °C (service temperature) of alloy 718. To initially validate the simulations, predicted phase fractions were benchmarked against high-energy X-ray diffraction data of multiple vendor-sourced alloy 718 samples and literature data, showing strong agreement. The strengthening phases γ′ and γ″, exhibit substantial variation (∼18 and 14 mole %, respectively), despite the elemental concentrations being adjusted within standardized ranges. Surrogate models were developed to conduct global sensitivity analysis using Sobol’ indices to identify the key elements contributing to overall phase % variabilities. Al emerged as the most influential element, with a 1.29 mole % of variation accounting for 86.24 % of γ′ phase % variability in aged condition. Remarkably, γ″, despite being Nb-based phase, showed significantly higher sensitivity (85.55 %) to Al than Nb. Our investigation revealed that increasing Al% lowers the γ″ solvus temperature, thus destabilizes it, and also suppresses its precipitation by significantly reducing Nb mobility in the matrix. By quantifying the sensitivity of phase fractions governing properties to compositional variability, this study offers critical guidelines for designing and certifying robust, reliable alloys by controlling compositions.
{"title":"Global sensitivity analysis for microstructural features to variability in elemental concentration of additively manufactured alloy 718","authors":"Hasan Al Jame , Jiayun Shao , Jixuan Dong , Pranav Karve , Kyle Mumm , Bryan A. Webler , Anthony D. Rollett , Sankaran Mahadevan , Tao Sun , S. Mohadeseh Taheri-Mousavi","doi":"10.1016/j.mtla.2025.102630","DOIUrl":"10.1016/j.mtla.2025.102630","url":null,"abstract":"<div><div>Alloy 718 (UNS N07718) is a widely utilized additively manufacturable superalloy for extreme-temperature applications for its superior mechanical properties. However, laser powder bed fusion of alloy 718 can exhibit yield strength variability of almost 400 MPa. Compositional variation during processing is one of the critical driving factors for such variation. Here, we combined validated calculation of phase diagrams (CALPHAD)-based integrated computational materials engineering (ICME) techniques to simulate microstructural features in as-built and fully-aged equilibrium conditions at 650 °C (service temperature) of alloy 718. To initially validate the simulations, predicted phase fractions were benchmarked against high-energy X-ray diffraction data of multiple vendor-sourced alloy 718 samples and literature data, showing strong agreement. The strengthening phases γ′ and γ″, exhibit substantial variation (∼18 and 14 mole %, respectively), despite the elemental concentrations being adjusted within standardized ranges. Surrogate models were developed to conduct global sensitivity analysis using Sobol’ indices to identify the key elements contributing to overall phase % variabilities. Al emerged as the most influential element, with a 1.29 mole % of variation accounting for 86.24 % of γ′ phase % variability in aged condition. Remarkably, γ″, despite being Nb-based phase, showed significantly higher sensitivity (85.55 %) to Al than Nb. Our investigation revealed that increasing Al% lowers the γ″ solvus temperature, thus destabilizes it, and also suppresses its precipitation by significantly reducing Nb mobility in the matrix. By quantifying the sensitivity of phase fractions governing properties to compositional variability, this study offers critical guidelines for designing and certifying robust, reliable alloys by controlling compositions.</div></div>","PeriodicalId":47623,"journal":{"name":"Materialia","volume":"45 ","pages":"Article 102630"},"PeriodicalIF":2.9,"publicationDate":"2025-12-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145798380","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 : 2025-12-08DOI: 10.1016/j.mtla.2025.102627
Subhas Bhunia , Poornachandra Satyampet , M.P. Gururajan , Shubo Wang , Harishchandra Singh , Al Rahemtulla , Prita Pant
In this study, we examine the effect of two different initial microstructures of a medium manganese steel on the kinetics of austenite reversion and elemental partitioning during intercritical annealing, using in-situ synchrotron and ex-situ scanning transmission electron microscopy (STEM)/atom probe tomography (APT) based elemental mapping. These microstructures are tempered-cold-rolled (TCR) and hot-rolled-quenched (HRQ) martensite. The HRQ specimen exhibits faster kinetics of austenite reversion and higher austenite volume fraction than the TCR specimen during intercritical annealing. However, after cooling to room temperature, HRQ specimen had less retained austenite than the TCR specimen. To identify the reasons behind different austenite stability, detailed analysis of elemental partitioning was carried out using synchrotron data for lattice parameters, as well as elemental mapping using STEM and APT. For the HRQ specimen, austenite growth during the first 20 min. occurs by carbon (C) partitioning, with increased manganese (Mn) concentration near the austenite–ferrite interface. In contrast, for the TCR specimen, growth of austenite is accompanied by C and Mn partitioning from the initial stage itself. These observations confirm that for the first 20 min. austenite growth occurs by the negligible partitioning local equilibrium (NPLE) mechanism for HRQ, and subsequently changes to partitioning local equilibrium (PLE), while the growth mode is PLE for TCR sample throughout intercritical annealing. Higher C and Mn enrichment leads to greater thermal stability of austenite in the TCR specimen. Hence the TCR sample has greater volume fraction of retained austenite for various annealing durations.
{"title":"An in-situ synchrotron study of austenite reversion kinetics and elemental partitioning during intercritical annealing","authors":"Subhas Bhunia , Poornachandra Satyampet , M.P. Gururajan , Shubo Wang , Harishchandra Singh , Al Rahemtulla , Prita Pant","doi":"10.1016/j.mtla.2025.102627","DOIUrl":"10.1016/j.mtla.2025.102627","url":null,"abstract":"<div><div>In this study, we examine the effect of two different initial microstructures of a medium manganese steel on the kinetics of austenite reversion and elemental partitioning during intercritical annealing, using in-situ synchrotron and ex-situ scanning transmission electron microscopy (STEM)/atom probe tomography (APT) based elemental mapping. These microstructures are tempered-cold-rolled (TCR) and hot-rolled-quenched (HRQ) martensite. The HRQ specimen exhibits faster kinetics of austenite reversion and higher austenite volume fraction than the TCR specimen during intercritical annealing. However, after cooling to room temperature, HRQ specimen had less retained austenite than the TCR specimen. To identify the reasons behind different austenite stability, detailed analysis of elemental partitioning was carried out using synchrotron data for lattice parameters, as well as elemental mapping using STEM and APT. For the HRQ specimen, austenite growth during the first 20 min. occurs by carbon (C) partitioning, with increased manganese (Mn) concentration near the austenite–ferrite interface. In contrast, for the TCR specimen, growth of austenite is accompanied by C and Mn partitioning from the initial stage itself. These observations confirm that for the first 20 min. austenite growth occurs by the negligible partitioning local equilibrium (NPLE) mechanism for HRQ, and subsequently changes to partitioning local equilibrium (PLE), while the growth mode is PLE for TCR sample throughout intercritical annealing. Higher C and Mn enrichment leads to greater thermal stability of austenite in the TCR specimen. Hence the TCR sample has greater volume fraction of retained austenite for various annealing durations.</div></div>","PeriodicalId":47623,"journal":{"name":"Materialia","volume":"45 ","pages":"Article 102627"},"PeriodicalIF":2.9,"publicationDate":"2025-12-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145749327","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 : 2025-12-07DOI: 10.1016/j.mtla.2025.102626
Kang Yang , Xiankun Wu , Zitao Jiang , Wei Zhou , Gobinda Gyawali , Shihong Zhang , Wenya Li
This study developed CuCrZr-Ti2AlC composite coatings via cold spraying to enhance the performance of copper alloy guide rails. The cold spray process was specifically selected to prevent the oxidation and decomposition of the MAX phase Ti2AlC. Composite powders with different Ti2AlC contents were prepared by mechanical alloying. The results indicate that the coating with 20 wt.%Ti2AlC achieves an optimal balance of a hardness of 173.40 HV0.5 and high electrical conductivity (6.62 μΩ·cm). Its specific wear rate under dry sliding was 1.30 × 10–4 mm3/(N·m), which is 86.4 % lower than that of the pure CuCrZr coating (9.59 × 10–4 mm3/(N·m)). Furthermore, under current loading, the wear rate of the 20 wt.%Ti2AlC coating (1.63 × 10–4 mm3/(N·m)) was significantly lower than that of the 30 wt.%Ti2AlC coating (3.51 × 10–4 mm3/(N·m)). The CuCrZr-20 wt.%Ti2AlC composite coating is thus a promising material for applications requiring simultaneous wear resistance and conductivity.
{"title":"Enhanced dry and current-carrying friction properties of cold-sprayed Ti2AlC reinforced CuCrZr coating","authors":"Kang Yang , Xiankun Wu , Zitao Jiang , Wei Zhou , Gobinda Gyawali , Shihong Zhang , Wenya Li","doi":"10.1016/j.mtla.2025.102626","DOIUrl":"10.1016/j.mtla.2025.102626","url":null,"abstract":"<div><div>This study developed CuCrZr-Ti<sub>2</sub>AlC composite coatings via cold spraying to enhance the performance of copper alloy guide rails. The cold spray process was specifically selected to prevent the oxidation and decomposition of the MAX phase Ti<sub>2</sub>AlC. Composite powders with different Ti<sub>2</sub>AlC contents were prepared by mechanical alloying. The results indicate that the coating with 20 <em>wt</em>.%Ti<sub>2</sub>AlC achieves an optimal balance of a hardness of 173.40 HV<sub>0.5</sub> and high electrical conductivity (6.62 μΩ·cm). Its specific wear rate under dry sliding was 1.30 × 10<sup>–4</sup> mm<sup>3</sup>/(N·m), which is 86.4 % lower than that of the pure CuCrZr coating (9.59 × 10<sup>–4</sup> mm<sup>3</sup>/(N·m)). Furthermore, under current loading, the wear rate of the 20 <em>wt</em>.%Ti<sub>2</sub>AlC coating (1.63 × 10<sup>–4</sup> mm<sup>3</sup>/(N·m)) was significantly lower than that of the 30 <em>wt</em>.%Ti<sub>2</sub>AlC coating (3.51 × 10<sup>–4</sup> mm<sup>3</sup>/(N·m)). The CuCrZr-20 <em>wt</em>.%Ti<sub>2</sub>AlC composite coating is thus a promising material for applications requiring simultaneous wear resistance and conductivity.</div></div>","PeriodicalId":47623,"journal":{"name":"Materialia","volume":"45 ","pages":"Article 102626"},"PeriodicalIF":2.9,"publicationDate":"2025-12-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145798378","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 : 2025-12-06DOI: 10.1016/j.mtla.2025.102623
Dharmendra K. Yadav , Deepak Paliwal , Surya D. Yadav , Subhasis Sinha
In the present work, the crystallographic texture dependence of the biocompatibility of a novel Ti35Zr35Nb15Mo5Fe5Cr5 complex concentrated alloy (CCA) in the as-cast and annealed states was investigated. In-vitro cell culture experiments using MG-63 cells demonstrated that the cell viability and proliferation of the annealed CCA were superior compared to the as-cast CCA. SEM images also showed higher cell adhesion (higher number density of adhered cells) on the annealed CCA sample. EBSD and X-ray texture measurements were performed to obtain the micro- and macro-texture evolution, respectively, in order to unravel the effect of crystallographic texture on the biocompatibility behavior of the as-cast and annealed CCA samples. The higher biocompatibility in the annealed specimen is related to texture evolution during annealing. While standard texture components were not distinctly observed in the as-cast specimen except some rotated Cube component, the annealed specimen showed the presence of γ-fiber, ε-fiber, and Brass components in addition to Cube component. The cell adhesion is sensitive to texture, with a greater number of cells attaching to grains that are crystallographically oriented with their normal to the surface exposed to the cells. This preferential cell attachment along accounts for the enhanced biocompatibility of the annealed CCA specimen as compared to the as-cast specimen.
{"title":"Crystallographic texture dependence of biocompatibility in a Ti35Zr35Nb15Mo5Fe5Cr5 complex concentrated alloy","authors":"Dharmendra K. Yadav , Deepak Paliwal , Surya D. Yadav , Subhasis Sinha","doi":"10.1016/j.mtla.2025.102623","DOIUrl":"10.1016/j.mtla.2025.102623","url":null,"abstract":"<div><div>In the present work, the crystallographic texture dependence of the biocompatibility of a novel Ti<sub>35</sub>Zr<sub>35</sub>Nb<sub>15</sub>Mo<sub>5</sub>Fe<sub>5</sub>Cr<sub>5</sub> complex concentrated alloy (CCA) in the as-cast and annealed states was investigated. In-vitro cell culture experiments using MG-63 cells demonstrated that the cell viability and proliferation of the annealed CCA were superior compared to the as-cast CCA. SEM images also showed higher cell adhesion (higher number density of adhered cells) on the annealed CCA sample. EBSD and X-ray texture measurements were performed to obtain the micro- and macro-texture evolution, respectively, in order to unravel the effect of crystallographic texture on the biocompatibility behavior of the as-cast and annealed CCA samples. The higher biocompatibility in the annealed specimen is related to texture evolution during annealing. While standard texture components were not distinctly observed in the as-cast specimen except some rotated Cube component, the annealed specimen showed the presence of γ-fiber, ε-fiber, and Brass components in addition to Cube component. The cell adhesion is sensitive to texture, with a greater number of cells attaching to grains that are crystallographically oriented with their normal to the surface exposed to the cells. This preferential cell attachment along accounts for the enhanced biocompatibility of the annealed CCA specimen as compared to the as-cast specimen.</div></div>","PeriodicalId":47623,"journal":{"name":"Materialia","volume":"45 ","pages":"Article 102623"},"PeriodicalIF":2.9,"publicationDate":"2025-12-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145798379","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 : 2025-12-06DOI: 10.1016/j.mtla.2025.102625
Jingwen Li , Cai Chen , Qiankun Tan , Xiaoxiao Ma , Jinglian Du , Jianwei Xiao , Zhonghua Du , Chuang Deng
Body-centered cubic (BCC) tungsten (W) exhibits a striking transition in deformation mechanisms under impact loading, yet the underlying criteria governing the competition between dislocation slip and twinning remain unresolved. Here, we combine molecular dynamics (MD) simulations and density functional theory (DFT) calculations to establish a stress-dependent framework for this mechanistic crossover. At low impact velocities (250–500 m/s), plasticity is mediated by dislocation activity, while twinning emerges as the plastic mechanism at velocities above 500 m/s. At 500 m/s impact velocity, twinning nucleation occurs via heterogeneous (dislocation-mediated) mechanisms, while at 2000 m/s, homogeneous nucleation becomes active through local phase transition mediation. DFT and MD reveal that compressive stress stabilizes metastable two-layer near-isosceles twin boundaries (near-isoTBs), reducing the energy barrier for twinning nucleation by altering the generalized stacking fault enthalpy (GSFH) profile. Stress-driven disconnection dissociation further governs twin growth kinetics. These findings quantitatively link intrinsic material properties (GSFH) and extrinsic loading conditions (stress states) to deformation pathways, providing design principles for BCC metals in high-strain-rate applications such as penetrators and impact-resistant structures.
{"title":"Impact-loading-driven dislocation-to-twinning transition in BCC tungsten: A generalized stacking fault enthalpy criterion","authors":"Jingwen Li , Cai Chen , Qiankun Tan , Xiaoxiao Ma , Jinglian Du , Jianwei Xiao , Zhonghua Du , Chuang Deng","doi":"10.1016/j.mtla.2025.102625","DOIUrl":"10.1016/j.mtla.2025.102625","url":null,"abstract":"<div><div>Body-centered cubic (BCC) tungsten (W) exhibits a striking transition in deformation mechanisms under impact loading, yet the underlying criteria governing the competition between dislocation slip and twinning remain unresolved. Here, we combine molecular dynamics (MD) simulations and density functional theory (DFT) calculations to establish a stress-dependent framework for this mechanistic crossover. At low impact velocities (250–500 m/s), plasticity is mediated by dislocation activity, while twinning emerges as the plastic mechanism at velocities above 500 m/s. At 500 m/s impact velocity, twinning nucleation occurs via heterogeneous (dislocation-mediated) mechanisms, while at 2000 m/s, homogeneous nucleation becomes active through local phase transition mediation. DFT and MD reveal that compressive stress stabilizes metastable two-layer near-isosceles twin boundaries (near-isoTBs), reducing the energy barrier for twinning nucleation by altering the generalized stacking fault enthalpy (GSFH) profile. Stress-driven disconnection dissociation further governs twin growth kinetics. These findings quantitatively link intrinsic material properties (GSFH) and extrinsic loading conditions (stress states) to deformation pathways, providing design principles for BCC metals in high-strain-rate applications such as penetrators and impact-resistant structures.</div></div>","PeriodicalId":47623,"journal":{"name":"Materialia","volume":"45 ","pages":"Article 102625"},"PeriodicalIF":2.9,"publicationDate":"2025-12-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145749328","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 : 2025-12-04DOI: 10.1016/j.mtla.2025.102622
Muhammad Wisnugroho , Fraser H.J. Laidlaw , Andrei V. Gromov , Colin Farquharson , Fabio Nudelman
Non-collagenous proteins (NCPs) are specialized biomacromolecules within the extracellular matrix (ECM) that regulate the mineralization of calcified tissues, such as bone and dentin. Numerous in vitro studies have demonstrated that natural polyanionic NCPs and their analogues can mediate intrafibrillar mineralization, characterized by the infiltration of apatite minerals into collagen fibrils. However, these studies primarily utilize self-assembled collagen fibrils or demineralized mature tissues, leaving it unclear whether pristine embryonic bone ECM at a developmental stage permissive to mineral deposition can regulate intrafibrillar mineralization independently or requires polyanionic NCP substitutes to promote the process artificially. To address this, we employed an ex vivo model of endochondral ossification using metatarsals isolated from 15-day-old embryonic mice (E15). In addition to a supersaturated calcium (Ca) and inorganic phosphate (Pi) medium, we introduced fetuin-A, a native polyanionic NCP or poly-DL-aspartic acid (pAsp), commonly used as an NCP substitute. The incorporation of either additive was essential for the effective mineralization of embryonic metatarsals. Both fetuin-A and pAsp played a direct role in facilitating the infiltration of Ca-Pi precursors into the avascular cartilaginous matrix. Raman spectroscopy and electron microscopy confirmed the formation of hydroxyapatite (HAp) exhibiting diverse levels of crystallinity, with fetuin-A supplementation resulting in the greatest HAp accumulation within the rudiments. HAp was localized in the perichondrium, a region conducive to initial mineralization and enriched with a fibrillar network of collagen types I and II. Three-dimensional reconstructions implementing Dijkstra’s algorithm revealed the association between HAp and collagen fibrils either organized in an intrafibrillar, extrafibrillar, or combined arrangement.
{"title":"Polyanionic non-collagenous proteins and their analogues promote artificial mineralization of embryonic mouse bone","authors":"Muhammad Wisnugroho , Fraser H.J. Laidlaw , Andrei V. Gromov , Colin Farquharson , Fabio Nudelman","doi":"10.1016/j.mtla.2025.102622","DOIUrl":"10.1016/j.mtla.2025.102622","url":null,"abstract":"<div><div>Non-collagenous proteins (NCPs) are specialized biomacromolecules within the extracellular matrix (ECM) that regulate the mineralization of calcified tissues, such as bone and dentin. Numerous <em>in vitro</em> studies have demonstrated that natural polyanionic NCPs and their analogues can mediate intrafibrillar mineralization, characterized by the infiltration of apatite minerals into collagen fibrils. However, these studies primarily utilize self-assembled collagen fibrils or demineralized mature tissues, leaving it unclear whether pristine embryonic bone ECM at a developmental stage permissive to mineral deposition can regulate intrafibrillar mineralization independently or requires polyanionic NCP substitutes to promote the process artificially. To address this, we employed an <em>ex vivo</em> model of endochondral ossification using metatarsals isolated from 15-day-old embryonic mice (E15). In addition to a supersaturated calcium (Ca) and inorganic phosphate (Pi) medium, we introduced fetuin-A, a native polyanionic NCP or poly-DL-aspartic acid (pAsp), commonly used as an NCP substitute. The incorporation of either additive was essential for the effective mineralization of embryonic metatarsals. Both fetuin-A and pAsp played a direct role in facilitating the infiltration of Ca-Pi precursors into the avascular cartilaginous matrix. Raman spectroscopy and electron microscopy confirmed the formation of hydroxyapatite (HAp) exhibiting diverse levels of crystallinity, with fetuin-A supplementation resulting in the greatest HAp accumulation within the rudiments. HAp was localized in the perichondrium, a region conducive to initial mineralization and enriched with a fibrillar network of collagen types I and II. Three-dimensional reconstructions implementing Dijkstra’s algorithm revealed the association between HAp and collagen fibrils either organized in an intrafibrillar, extrafibrillar, or combined arrangement.</div></div>","PeriodicalId":47623,"journal":{"name":"Materialia","volume":"45 ","pages":"Article 102622"},"PeriodicalIF":2.9,"publicationDate":"2025-12-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145698132","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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