Materialia最新文献

{"title":"In-flight reduction of iron oxides from various sources by hydrogen plasma","authors":"Jordan N. Figueiredo,&nbsp;Bassam B. Dally,&nbsp;Deanna A. Lacoste","doi":"10.1016/j.mtla.2026.102658","DOIUrl":"10.1016/j.mtla.2026.102658","url":null,"abstract":"<div><div>This study demonstrates in-flight reduction using a stable, elongated-arc hydrogen plasma for three iron-bearing feedstocks: pure hematite, combusted iron from the MC<span><math><msup><mrow></mrow><mrow><mn>2</mn></mrow></msup></math></span> burner in TuE Eindhoven, and goethite. Despite not being designed for process performance, a high absolute reduction degree was achieved (71%–76% for hematite/combusted iron; 42% for aluminum-bearing goethite) at short residence times (18-30<!--> <!-->ms) with an efficiency of 26.8<!--> <!-->g<span><math><msub><mrow></mrow><mrow><mi>i</mi><mi>r</mi><mi>o</mi><mi>n</mi></mrow></msub></math></span>/kWh. SEM shows that in-flight melting modifies combustion-induced morphological defects in combusted iron particles (e.g., cracks and hollow-sphere structures), confirming technical feasibility for iron production and the iron-power cycle. Goethite-rich feed benefits from rapid dehydroxylation. However, even small gangue fractions, especially aluminum phases, promote iron–aluminum spinel formation that impedes fast reduction. Because gangues are not removed by this route, they must be managed separately. These results indicate clear paths towards practical application: enclosing the plasma–particle interaction zone, extending residence time, and systematically testing lower-grade ores with spinel formation mitigation strategies.</div></div>","PeriodicalId":47623,"journal":{"name":"Materialia","volume":"45 ","pages":"Article 102658"},"PeriodicalIF":2.9,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145977821","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":"Modeling the bainite transformation kinetics during isothermal holding and continuous cooling for different carbon concentrations","authors":"Bernhard Bloder ,&nbsp;Bernd Schuscha ,&nbsp;Dominik Brandl ,&nbsp;Thomas Antretter ,&nbsp;Peter Raninger","doi":"10.1016/j.mtla.2025.102637","DOIUrl":"10.1016/j.mtla.2025.102637","url":null,"abstract":"<div><div>In this work we develop a bainite model which can describe bainite formation for arbitrary cooling conditions. To investigate the influence of carbon on bainite formation, the model is applied to a set of steels with different carbon concentrations and heat treatments. For the investigated steels the <span><math><msubsup><mrow><mi>T</mi></mrow><mrow><mn>0</mn></mrow><mrow><msup><mrow></mrow><mrow><mo>′</mo></mrow></msup></mrow></msubsup></math></span> temperature and the prior austenite grain size are measured and used in the calculation. The redistribution of carbon is considered and the respective parameters are given a carbon dependency. The efforts to get a consistent set of parameters are laid out. The calculations for isothermal bainite formation and bainite formation upon continuous cooling are compared to data from dilatometer and XRD measurements.</div></div>","PeriodicalId":47623,"journal":{"name":"Materialia","volume":"45 ","pages":"Article 102637"},"PeriodicalIF":2.9,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145885049","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":"The formation mechanism and kinetics of Ni3GaAs nano-thin films on GaAs","authors":"M. Charai ,&nbsp;C. Perrin-Pellegrino ,&nbsp;D. Mangelinck ,&nbsp;S. Rabhi ,&nbsp;A. Portavoce ,&nbsp;M. Putero ,&nbsp;K. Hoummada","doi":"10.1016/j.mtla.2026.102689","DOIUrl":"10.1016/j.mtla.2026.102689","url":null,"abstract":"<div><div>A thorough investigation of metal–semiconductor contacts is essential for advancing the design and fabrication of scaled devices based on III-V compound semiconductors. The initial stages of growth and the kinetics of the Ni₃GaAs phase at both coherent and incoherent Ni/GaAs interfaces have primarily been studied using <em>in situ</em> X-ray diffraction (XRD) measurements, transmission electron microscopy (TEM), and atom probe tomography (APT) analysis. In this study, we validate the hypothesis that variations in XRD integrated intensity are proportional to the thickness of the formed phase by performing direct measurements using TEM and <em>in situ</em> XRD. In situ XRD measurements were then carried out during isothermal annealing at different temperatures on two samples with Ni film thicknesses of 20 nm and 100 nm, in order to monitor the growth kinetics of the sole Ni₃GaAs phase formed. The results demonstrate that only the Ni vacancy diffusion mechanism is dominant in this phase, and that there is strong agreement between the Ni₃GaAs growth kinetics observed in nano thin films and those reported for bulk diffusion couples. By comparing these findings with nucleation and growth models, we conclude that the growth of the Ni₃GaAs phase at the Ni/GaAs interface is predominantly diffusion-controlled at low temperatures and larger thicknesses, whereas it is mainly governed by interface reactions at higher temperatures and smaller thicknesses.</div></div>","PeriodicalId":47623,"journal":{"name":"Materialia","volume":"45 ","pages":"Article 102689"},"PeriodicalIF":2.9,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147420707","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":"Vacancy complexes in GaN single crystals","authors":"Jakub Čížek ,&nbsp;František Hájek ,&nbsp;Ewa Grzanka ,&nbsp;Filip Dominec ,&nbsp;Karla Kuldová ,&nbsp;Tomáš Hubáček ,&nbsp;Alice Hospodková ,&nbsp;Roman Hrytsak ,&nbsp;Mike Leszczynski ,&nbsp;Tomasz Sochacki ,&nbsp;Robert Kucharski ,&nbsp;Robert Czernecki ,&nbsp;Rudolf Shymon ,&nbsp;Romana Kučerková ,&nbsp;Jan Kuriplach ,&nbsp;Oksana Melikhova","doi":"10.1016/j.mtla.2026.102681","DOIUrl":"10.1016/j.mtla.2026.102681","url":null,"abstract":"<div><div>The paper presents a systematic investigation of point defects in a series of high-quality GaN crystals grown through halide vapor phase epitaxy (HVPE) and ammonothermal synthesis (AM). The GaN crystals were characterized using positron annihilation spectroscopy (PAS), along with measurements of photoluminescence (PL) and <em>ab-initio</em> modelling of various point defect configurations and calculations of positron lifetimes. The concentration of impurities in each GaN crystal was determined using secondary ion mass spectrometry. Our study revealed that the concentration of gallium vacancies (V_Ga) in GaN crystals is influenced by the levels of hydrogen and oxygen impurities. Most HVPE GaN crystals exhibit low concentrations of hydrogen and oxygen, with no defects detectable by PAS. Only one HVPE crystal showed an enhanced concentration of oxygen, which is associated with V_Ga, forming negatively charged V_Ga+O_N complexes, where one nitrogen nearest neighbour of the vacancy is substituted by oxygen. In contrast, AM GaN crystals contain at least two orders of magnitude higher concentrations of hydrogen and oxygen impurities. This results in a high concentration (≥ 10¹⁸ cm⁻³) of V_Ga complexes with H and/or O. The configuration of these complexes is determined by the ratio of hydrogen to oxygen concentration within the crystal. The undoped n-type AM GaN crystal contains V_Ga+2H+O_N complexes, while the manganese-doped semi-insulating AM crystal contains V_Ga+3H complexes, both complexes being in neutral charge state. The PL results provide evidence that the V_Ga+2H+O_N and V_Ga+3H complexes are the source of the green emission bands at 2.34 eV and 2.37 eV, respectively, in AM crystals.</div></div>","PeriodicalId":47623,"journal":{"name":"Materialia","volume":"45 ","pages":"Article 102681"},"PeriodicalIF":2.9,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146187835","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":"Cellulose nanofibers in ice: microstructural effects on mechanical response","authors":"Emily Asenath-Smith ,&nbsp;Kiera L. Thompson Towell ,&nbsp;Matthew A. Fort,&nbsp;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":"2026-03-01","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}

{"title":"A strategy for reducing yield-to-tensile ratio in HSLA steel: induced elemental partitioning to promote reverse austenite formation","authors":"Borui Ren ,&nbsp;Ye Cui ,&nbsp;Tenglong Gong ,&nbsp;Xiyuan Xiao ,&nbsp;Lixin Sun ,&nbsp;Yang Zhang ,&nbsp;Yuxin Wu ,&nbsp;Tan Zhao ,&nbsp;Gang Zhao ,&nbsp;Zhongwu Zhang","doi":"10.1016/j.mtla.2025.102642","DOIUrl":"10.1016/j.mtla.2025.102642","url":null,"abstract":"<div><div>High-strength low-alloy (HSLA) steels have emerged as a candidate material in engineering applications, attributed to their balanced strength, good plasticity, and favorable weldability. However, stabilizing film-like reverse austenite (RA) at room temperature is difficult due to low alloy content of HSLA steels, which becomes a challenge to prevent the concurrent achievement of high elongation and a low yield-to-tensile ratio. In this study, a martensite-based microstructure featuring stable film-like RA and uniformly distributed Cu-rich nanoprecipitates is successfully produced in a low-alloy steel through a process involving quenching, cold rolling with 2% deformation, lamellarization, and tempering. The results reveal that 2% deformation induces dislocations, which effectively control fresh martensite (FM) with higher length-to-diameter (<em>L/D</em>) ratio and an initial Ni enrichment of 4.67%. Additionally, the partitioning of Ni elements during tempering creates conditions for the precipitation of uniform film-like RA. This stabilized film-like RA provides significant work-hardening capacity which enables the simultaneous achievement of high elongation (26.7%) and a low yield-to-tensile ratio (0.88) while maintaining a high yield strength of 922 MPa. This study introduces a novel strategy for developing high-performance HSLA steels, offering an effective paradigm to address the long-standing challenge of concurrently achieving high elongation and a low yield-to-tensile ratio, which are typically conflicting properties in these materials.</div></div>","PeriodicalId":47623,"journal":{"name":"Materialia","volume":"45 ","pages":"Article 102642"},"PeriodicalIF":2.9,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145841445","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 novel folded cup energy absorption structure: Design and validation","authors":"Qiqi Li ,&nbsp;Fanjiao He ,&nbsp;Congrui Xie ,&nbsp;Kai Liu ,&nbsp;Hui Gao ,&nbsp;Ping Zou ,&nbsp;Lin Hu","doi":"10.1016/j.mtla.2025.102646","DOIUrl":"10.1016/j.mtla.2025.102646","url":null,"abstract":"<div><div>In this study, inspired by the design of a step-folding cup, a similar structure, the novel folded cup energy absorption structure (FES), was proposed. This structure is fabricated using selective laser sintering (SLS) technology with nylon 11. Through rigorous simulation analysis, the energy absorption characteristics of the FES have been systematically elucidated. Subsequently, the deformation behavior and mechanical properties under axial compression were investigated using finite element analysis (FEA) and practical experimentation. FES achieves unique mechanical characteristics, including negative stiffness and a novel deformation mode. To validate the effectiveness of the proposed structure, a comparative analysis was conducted between experimental and simulation results. This paper analyzes the compressive mechanical properties of the FES from four perspectives: the diameter of each layer, the thickness of the inclined buffer layer, the number of layers, and the proportion of the inclined buffer layer at the end. The findings demonstrate that a decrease in diameter deviation, in essence, is positively correlated with both the dimensional ratio and the thickness of the inclined buffer layer, leading to significantly improved energy absorption capabilities in the FES model. Compared to the experimental benchmark model, the parametric model demonstrates up to 112.58% enhancement in specific energy absorption.</div></div>","PeriodicalId":47623,"journal":{"name":"Materialia","volume":"45 ","pages":"Article 102646"},"PeriodicalIF":2.9,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145841508","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":"Porcine acellular dermal matrix facilitates hair follicle stem cells entering the hair cycle in C57/BL6 mice","authors":"Dar-Jen Hsieh ,&nbsp;Srinivasan Periasamy ,&nbsp;Ko-Chung Yen ,&nbsp;Dur-Zong Hsu ,&nbsp;Su-Shin Lee","doi":"10.1016/j.mtla.2026.102669","DOIUrl":"10.1016/j.mtla.2026.102669","url":null,"abstract":"<div><div>Alopecia is a skin disease characterized by hair loss, which mainly distresses mental health and quality of life. A rise in the number of alopecia cases is evolving due to a variety of factors. We developed a porcine collagen acellular dermal matrix (ADM) using supercritical carbon dioxide (SCCO₂) extraction technology. We then cryo-ground the ADM into particles, ranging from 50–150 μm, named ADM scaffolds. In the present study, we used C57BL/6 mice injected with ADM scaffold and evaluated hair growth with and without mice Platelet-Rich Plasma (PRP), to evaluate its efficacy in hair regeneration. The combination of the ADM scaffold and mice PRP exhibited a synergistic effect. Hair growth was observed in ADM scaffold-treated mice in a time-dependent manner. Subdermal injection of the ADM scaffold enabled a serial cascade of stem cell differentiation markers for hair regeneration. ADM scaffold injected in the subdermal layer of the skin was found to modulate the CD34-positive stem cells and then followed by the expression of the hair cycle differentiation-related markers Sox9, Wnt3a, β-catenin, Ki67, and Lef-1, thereby modulating the hair cycle and increasing the hair follicles. To conclude, SCCO₂-derived porcine ADM scaffold increased hair follicles and hair density and might be a therapeutic solution for alopecia, without any adverse effects.</div></div>","PeriodicalId":47623,"journal":{"name":"Materialia","volume":"45 ","pages":"Article 102669"},"PeriodicalIF":2.9,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146037642","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":"Deformation mechanisms of dual-phase high entropy alloy with 9R structures at ambient and cryogenic temperatures","authors":"Min Peng ,&nbsp;Zhixue Cheng ,&nbsp;Yeqing Cai ,&nbsp;Yongjiang Jiang ,&nbsp;Jingjing Zhao ,&nbsp;Xi Zhu ,&nbsp;Lixia Wang","doi":"10.1016/j.mtla.2026.102663","DOIUrl":"10.1016/j.mtla.2026.102663","url":null,"abstract":"<div><div>The role of 9R structures in mediating phase transformations and mechanical properties of high-entropy alloys (HEAs) remains inadequately understood. This study investigates the tensile behavior of an Fe₄₀Mn₃₅Co₂₀Cr₅ HEA containing pre-existing 9R structures at both room temperature and 77 K. Results confirm the operation of a transformation-induced plasticity (TRIP) effect under both conditions. It is noteworthy that the low-temperature environment not only enables the stable existence of 9R structures but also promotes a massive phase transformation into a hexagonal close-packed (HCP) structure, consequently leading to the formation of a rarely reported HCP network structure at cryogenic temperatures. The synergistic interaction among the 9R structures, stacking faults, dislocations, and the HCP network enables the alloy to achieve significantly enhanced strength at 77 K without compromising ductility. A key finding is the crystallographic alignment between the 9R and the newly formed HCP structures, providing direct evidence for the role of 9R as a potent TRIP enhancer. Supported by a proposed crystallographic model for the 9R→HCP transformation, this work offers critical insights for designing advanced cryogenic structural materials leveraging 9R-phase engineering.</div></div>","PeriodicalId":47623,"journal":{"name":"Materialia","volume":"45 ","pages":"Article 102663"},"PeriodicalIF":2.9,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146077435","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":"Unlocking the synergy: How tip-radius and crystal orientation govern indentation in ferrous FCC alloys","authors":"Arka Mandal ,&nbsp;Sankalp Biswal ,&nbsp;Shiv Brat Singh,&nbsp;Debalay Chakrabarti","doi":"10.1016/j.mtla.2025.102621","DOIUrl":"10.1016/j.mtla.2025.102621","url":null,"abstract":"<div><div>The present study investigates the synergistic effects of indenter tip-radius and crystallographic orientation on the nanoindentation response of a ferrous FCC alloy, i.e. 304 austenitic stainless steel, combining experimental nanoindentation and molecular dynamics (MD) simulations. Although considerable research attention has been paid to the individual effects of crystal orientation and tip-radius, their combined influence on the indentation response of these alloys is still not well explored. This investigation concentrates on grains having different crystallographic orientations for various indenter geometries (tip-radii), which is of primary importance to relate mechanical response with microstructural features as well as identify where such differences in micro-mechanics originate. Grain 1, i.e., (111), having poor slip plane alignment, is the stiffest, while Grain 2, i.e., (100) with favorable slip plane orientations, is found to pose the least resistance to deformation. MD simulations provide insight into the details of occurring dislocation dynamics, such as Shockley partials, Stair-rod, and Hirth dislocations, with respect to their role in accommodating strains and the load-dip phenomenon. Distinct deformation mechanisms between sharp Berkovich (by the formation of prismatic dislocation loop) and spherical (by the formation of perfect stacking fault tetrahedron) indenters emphasize the influence of tip geometry on the development of dislocation substructure. This study bridges the gap between the fundamental mechanics of deformation and the application-oriented design of materials for developing these alloys with enhanced strength, reliability, and resistance to complex modes of loading.</div></div>","PeriodicalId":47623,"journal":{"name":"Materialia","volume":"45 ","pages":"Article 102621"},"PeriodicalIF":2.9,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145749329","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}