Materials Characterization最新文献

{"title":"Microstructure evolution and mechanical properties of partial transient liquid phase bonding of Si3N4/GH4169 joints using Ti/Cu/Ni/Cu composite interlayer","authors":"Yue Wen,&nbsp;Jie Zhang,&nbsp;Liangbo Sun,&nbsp;Chunfeng Liu,&nbsp;Zengwei Li","doi":"10.1016/j.matchar.2026.117218","DOIUrl":"10.1016/j.matchar.2026.117218","url":null,"abstract":"<div><div>To achieve high-strength Si₃N₄/GH4169 joints for elevated-temperature service, a Ti/Cu/Ni/Cu composite interlayer was designed for partial transient liquid phase bonding to form a seam dominated by heat-resistant solid solutions. Thermodynamic and phase-diagram analyses indicated that the Cu-Ti liquid reacted with Si₃N₄ to form a TiN reaction layer, while dissolution of the Ni layer raised the liquidus temperature, driving isothermal solidification into a ductile Cu-Ni solid solution ((Cu,Ni)(s,s)) matrix. This isothermal solidification also bonded the Ni layer to the GH4169 substrate. Differential scanning calorimetry on a model Cu/Ni couple verified essentially complete isothermal solidification within 20 min at 1120 °C. Joints were bonded at 1090–1180 °C for 10–25 min with 4–12 μm Ti layers. The typical joint microstructure was Si₃N₄/TiN+Ni₃Si/(Cu,Ni)(s,s) + Cu₄Ti + CuTi/Ni layer/(Cu,Ni)(s,s)/Ni(s,s)/GH4169. Increasing the bonding temperature or Ti layer thickness thickened the ceramic-side TiN layer and promoted the band-like aggregation of intermetallic compounds (IMCs), whereas prolonged holding mainly thickened the TiN layer. Microstructure-based two-dimensional finite element simulations showed that the ductile (Cu,Ni)(s,s) matrix relieved stress concentration, whereas IMC aggregation, TiN layer thickening, and a reduced (Cu,Ni)(s,s) fraction increased the maximum Mises and tensile stresses on the Si₃N₄ side. The joint bonded at 1120 °C for 20 min with an 8 μm Ti layer achieved a maximum room-temperature shear strength of ~67 MPa, with shear strengths of ~76 and ~33 MPa at 500 °C and 900 °C, respectively. This work provides a basis for designing heat-resistant Si₃N₄/GH4169 joints.</div></div>","PeriodicalId":18727,"journal":{"name":"Materials Characterization","volume":"241 ","pages":"Article 117218"},"PeriodicalIF":6.2,"publicationDate":"2026-10-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149213889","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Interlayer valley temperature-regulated microstructural evolution and high-temperature wear resistance of WAAM hardfacing layers","authors":"Haitao Lin,&nbsp;Shengfu Yu,&nbsp;Shitian Hu,&nbsp;Jindou Cao,&nbsp;Jie Jin,&nbsp;Tianying He,&nbsp;Zhenyu Yu","doi":"10.1016/j.matchar.2026.117159","DOIUrl":"10.1016/j.matchar.2026.117159","url":null,"abstract":"<div><div>Wire arc additive manufacturing (WAAM) is promising for die repair and remanufacturing, but uncontrolled heat accumulation during multilayer deposition can cause microstructural instability and inadequate high-temperature wear resistance. In this study, an interlayer valley temperature regulation (IVTR) strategy was developed for a self-designed Cr–Mo–V hardfacing alloy to regulate heat accumulation and convert it into an in situ subcritical thermal treatment effect. Compared with the deposited metal without IVTR, the IVTRed hardfacing metal experienced more sufficient subcritical thermal exposure, promoting retained austenite decomposition and the precipitation of fine secondary carbides, increasing the average hardness from 47.71 ± 0.62 HRC to 55.99 ± 0.53 HRC. Consequently, the IVTR sample yielding a 42.5% reduction in the steady-state average friction coefficient and a 38.9% decrease in the specific wear rate. The enhanced thermal exposure via IVTR also improved the load-bearing capacity and tribo-oxide film stability, shifting the dominant wear mechanism from adhesive wear and fatigue delamination to oxidative wear accompanied with a more continuous O-rich tribo- film. This study leverages the residual thermal energy from WAAM for in situ heat treatment, thereby eliminating post-repair heat treatment and reducing associated costs in the die repair workflow.</div></div>","PeriodicalId":18727,"journal":{"name":"Materials Characterization","volume":"240 ","pages":"Article 117159"},"PeriodicalIF":6.2,"publicationDate":"2026-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149199352","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Orientation-dependent deformation and subsurface damage mechanisms of sulfur-doped InP wafers under indentation loading","authors":"Junjiang Zhou,&nbsp;Hua Wei,&nbsp;Jiayun Deng,&nbsp;Hanbao Liu,&nbsp;Jie Yang,&nbsp;Chong Wang,&nbsp;Feng Qiu,&nbsp;Feng Hui,&nbsp;Xueqin Pang,&nbsp;Bin Yang","doi":"10.1016/j.matchar.2026.117124","DOIUrl":"10.1016/j.matchar.2026.117124","url":null,"abstract":"<div><div>Sulfur-doped indium phosphide (InP) is an important III–V compound semiconductor used in high-speed optoelectronic and photonic devices. Its brittle and anisotropic response makes it susceptible to orientation-dependent deformation, cracking and subsurface damage during precision machining. Molecular dynamics simulations, nanoindentation experiments, focused ion beam (FIB) cross-sectioning and cross-sectional transmission electron microscopy (XTEM) were combined to investigate indentation-induced deformation and damage in sulfur-doped InP wafers with (100), (110) and (111) orientations. Crystallographic orientation strongly affected plasticity initiation, defect evolution and crack propagation. The (100) plane showed early plastic activation, extensive multi-slip activity, dense interconnected dislocation networks and the greatest measured longitudinal crack penetration of 19.50 μm. The (110) plane exhibited more localised deformation and the shallowest penetration depth of 14.03 μm, although interacting transverse cracks produced pronounced surface spalling. The (111) plane showed delayed defect nucleation, the highest hardness and the greatest elastic recovery (24.82%), but developed long radial cracks and a penetration depth of 15.27 μm, together with deeper defect propagation and localised lattice rotation. HRTEM and diffraction analyses further revealed orientation-dependent lattice distortion and localised structural disorder near cracks. When considered together with the pop-in response, dislocation structures, strain localisation and crack morphology, maximum resolved shear stress analysis provided a qualitative crystallographic interpretation of the measured damage-depth ranking of (100) &gt; (111) &gt; (110). These findings show that each orientation has a distinct combination of surface and subsurface damage and provide a mechanistic basis for orientation-aware damage control during precision machining.</div></div>","PeriodicalId":18727,"journal":{"name":"Materials Characterization","volume":"240 ","pages":"Article 117124"},"PeriodicalIF":6.2,"publicationDate":"2026-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149199355","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effect of Sc-Zr alloying and aging treatment on the microstructure and properties of Al-Ce alloy by continuous rheo-extrusion","authors":"Qing Yang,&nbsp;Minqiang Gao,&nbsp;Yan Liu,&nbsp;Yunhe Ning,&nbsp;Huifang Pang,&nbsp;Chong Du,&nbsp;Renguo Guan","doi":"10.1016/j.matchar.2026.117137","DOIUrl":"10.1016/j.matchar.2026.117137","url":null,"abstract":"<div><div>Al-Ce alloys have attracted considerable attention as promising candidates for high-strength and heat-resistant structural applications. In this work, a hypereutectic Al–12 wt% Ce alloy fabricated via continuous rheo-extrusion was investigated to elucidate the effects of scandium (Sc) and zirconium (Zr) co-addition and subsequent aging treatment on microstructural evolution and mechanical properties. To maximize the precipitation hardening impact while avoiding the formation of coarse primary phases, a comparative analysis was conducted by introducing varying contents of Sc and Zr, based on the eutectic composition of the Al–Sc–Zr system and the optimal Sc/Zr atomic ratio for forming nano precipitates. The results showed that the synergistic addition of 0.4 wt% Sc and 0.16 wt% Zr refined the primary Al₁₁Ce₃ phase and reduced eutectic interlamellar spacing, which was due to the adsorption of Sc and Zr atoms at the α-Al/Al₁₁Ce₃ interface. Furthermore, this addition also promoted grain refinement and recrystallization during continuous rheo-extrusion. Thermal exposure tests at elevated temperatures demonstrated the Al–12Ce–0.4Sc–0.16Zr alloy possessed marked precipitation hardening responses, reaching peak hardness values of 92 HV at 300 °C for 20 h and 91 HV at 400 °C for 2 h, followed by excellent thermal stability upon prolonged exposure. Aging at 320 °C for 6 h, the uniformly distributed nanoscale Al₃(Sc, Zr) precipitates were formed. The strength of the alloy was enhanced by the interaction between dislocations and precipitates. The alloy achieved a yield strength of 222 MPa, an ultimate tensile strength of 265 MPa and an elongation of 6.3%. This study demonstrates that the combination of continuous rheo-extrusion and Sc-Zr microalloying provides an effective pathway for developing high-strength, heat-resistant Al-Ce based alloys.</div></div>","PeriodicalId":18727,"journal":{"name":"Materials Characterization","volume":"240 ","pages":"Article 117137"},"PeriodicalIF":6.2,"publicationDate":"2026-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149199270","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Microstructural evolution and corrosion behavior of HVAF-sprayed TiC-reinforced 316L coatings on high-strength aluminum alloy","authors":"Wei Li,&nbsp;Chenchen Liu,&nbsp;Kai Zhao,&nbsp;Zhen Qin,&nbsp;Xiangyong Meng,&nbsp;Qiang Li,&nbsp;Jinzhao Sun,&nbsp;Fengshi Yin,&nbsp;Zongqing Ma","doi":"10.1016/j.matchar.2026.117142","DOIUrl":"10.1016/j.matchar.2026.117142","url":null,"abstract":"<div><div>High-strength Al-Zn-Mg-Cu alloys are susceptible to localized corrosion in chloride-containing environments, and protective coatings require both effective barrier properties and electrochemical stability. In this work, 316L stainless steel coatings reinforced with 0–5 wt% TiC were deposited on 7A04 aluminum alloy by high-velocity air-fuel spraying to investigate the effects of TiC addition on coating microstructural evolution and corrosion behavior. With increasing TiC addition, the coatings exhibited enhanced splat flattening and a reduction in apparent porosity from 0.94% to 0.38%, accompanied by changes in powder feeding and deposition behavior. EBSD and TEM analyses revealed deformation-induced heterogeneous structures characterized by high dislocation densities, deformation twins, and locally refined grains. However, the corrosion response exhibited a non-monotonic trend. Short-term electrochemical tests showed slightly better polarization and impedance responses for the TiC-free coating, whereas the 1 wt% TiC coating exhibited the most stable surface condition after 7-day immersion. XPS analysis revealed differences in passive-film chemistry, with the 1 wt% TiC coating showing higher contributions from protective Cr- and Mo-containing oxide species, while surface-potential and post-corrosion observations indicated greater local heterogeneity at higher reinforcement contents. These results demonstrate that the corrosion response evolves non-monotonically with TiC addition and is governed by the interplay among coating structure, passive-film characteristics, local compositional heterogeneity, and deposition-related factors.</div></div>","PeriodicalId":18727,"journal":{"name":"Materials Characterization","volume":"240 ","pages":"Article 117142"},"PeriodicalIF":6.2,"publicationDate":"2026-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149199272","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effect of post-weld heat treatment on microstructural evolution and mechanical properties of Ti2AlNb alloy","authors":"Hao Zhang,&nbsp;Le Zai,&nbsp;Yun Wang,&nbsp;Xiaohuai Xue","doi":"10.1016/j.matchar.2026.117127","DOIUrl":"10.1016/j.matchar.2026.117127","url":null,"abstract":"<div><div>Ti₂AlNb alloys, by virtue of their unique O phase (Ti₂AlNb), have effectively resolved the long-standing brittleness issue associated with Ti–Al-based alloys, thereby substantially enhancing their mechanical properties. However, during welding processes, where high heat input is combined with rapid cooling, significant microstructural heterogeneity arises across the base metal (BM), heat-affected zone (HAZ), and fusion zone (FZ). Specifically, the FZ consists solely of a single B2 phase with coarse grains, in stark contrast to the fine equiaxed grains of the BM, which predisposes the welded joint to severe brittle fracture. In this study, post-weld heat treatment (PWHT) was employed to regulate the phase constituents and their volume fractions in different regions of the Ti₂AlNb alloy joint, with the aim of optimizing its mechanical properties. The results indicate that after solution treatment (ST) at 850 °C and 900 °C for 1 h, a large amount of O phase along with a small amount of α2 phase precipitated, leading to a progressive increase in room-temperature elongation (EL). When the solution temperature was increased to 950 °C, the welded joint consisted of 48.5% B2 phase, 50.4% O phase, and 1.2% α2 phase, achieving a room-temperature EL of 3.9%, which represents a 20% improvement over the as-welded joint. In contrast, when the solution temperature reached 1100 °C, the joint remained predominantly B2 phase, with no improvement in mechanical performance. The combined treatment of solution at 950 °C for 1 h followed by aging at 800 °C effectively promoted further precipitation of the O phase. However, with prolonged aging time, the morphology of the O phase gradually coarsened. After aging for 24 h, the joint achieved a maximum ultimate tensile strength (UTS) of 983.2 MPa, which was 57.4 MPa higher than that of the as-welded specimen. High-temperature in-situ tensile testing conducted at 650 °C revealed that during prolonged exposure at elevated temperature, a substantial amount of O phase and α2 phase precipitated from the B2 matrix in the solution-treated joint. Cracks preferentially initiated at the α2 phases and subsequently propagated along grain boundaries, ultimately leading to joint failure.</div></div>","PeriodicalId":18727,"journal":{"name":"Materials Characterization","volume":"240 ","pages":"Article 117127"},"PeriodicalIF":6.2,"publicationDate":"2026-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149199436","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Insights into texture inheritance and evolution of cold-rolled near-α titanium alloy tubes during recrystallization annealing","authors":"J.Z. Wang,&nbsp;H. Yang,&nbsp;Y.Y. Chen,&nbsp;Z.P. Shangguan,&nbsp;D. Wei,&nbsp;H. Li","doi":"10.1016/j.matchar.2026.117086","DOIUrl":"10.1016/j.matchar.2026.117086","url":null,"abstract":"<div><div>Titanium alloy tubes attract increasing application in aerospace, marine, and energy fields due to their excellent properties. But the texture evolution of titanium alloy tubes during the intermediate recrystallization annealing process and the underlying mechanisms remain unclear. In this work, taking the cold-rolled titanium alloy tubes with tangential texture (TT tube) and normal texture (NT tube) as the material case, the microstructure and texture evolution of the material after annealing at different temperatures were investigated via EBSD observation and analysis. The main insights include: (1) The TT tube showed an obvious texture transformation from tangential texture to a tangential direction (TD)-split basal texture, because a portion of grains exhibiting a normal texture has higher stored energy than those with a tangential texture, making them more prone to recrystallization nucleation. (2) The NT tubes inherited the initial normal texture because the recrystallized grains tend to inherit the c-axis orientation of parent grains. (3) In the TT tube and the fine-grained normal-texture tube (NT-FG), cold-rolling induced activation of prismatic slip generated a large number of 30°/[0001] grain boundaries, thereby facilitating the nucleation of new grains with 〈11−20〉//RD orientation during annealing. The grains with this orientation exhibited preferential growth during the grain growth stage, resulting in the texture transformation from 〈10−10〉//RD to 〈11–20〉//RD. In contrast, the coarse-grained normal-texture tube (NT-CG) exhibited a lower stored energy state, leading to fewer nucleated grains. The grains with the 〈11–20〉//RD orientation failed to dominate the grain growth stage, so this texture transformation did not occur. These results demonstrate that the texture inheritance and evolution during annealing are closely related to the texture type and stored energy of cold-rolled titanium alloy tubes. The insights gained from this study may serve as a valuable foundation for the development of high-performance titanium alloy tubes.</div></div>","PeriodicalId":18727,"journal":{"name":"Materials Characterization","volume":"240 ","pages":"Article 117086"},"PeriodicalIF":6.2,"publicationDate":"2026-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149199428","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Microstructure, thermal, mechanical and tribological properties of Cu composites reinforced with Ag-decorated Ti3C2Tx nanosheets","authors":"Huadong Ye,&nbsp;Haohao Zou,&nbsp;Xinru Gong,&nbsp;Weiwei Zhu,&nbsp;Ying Han,&nbsp;Pan Dong,&nbsp;Xu Ran","doi":"10.1016/j.matchar.2026.117120","DOIUrl":"10.1016/j.matchar.2026.117120","url":null,"abstract":"<div><div>Aerospace, rail transportation, and electronics require Cu-based materials with high thermal conductivity together with adequate mechanical and tribological performance. However, the relatively low strength, hardness, and wear resistance of Cu limit its use under demanding service conditions. Herein, Ti₃C₂T_x MXene nanosheets were decorated with Ag nanoparticles, and Ti₃C₂T_x@Ag/Cu composites were fabricated by ball milling followed by fast hot-press sintering. Ag nanoparticles were uniformly distributed on the Ti₃C₂T_x surfaces, and the addition of Ti₃C₂T_x@Ag progressively refined the Cu matrix grains from 5.31 μm in pure Cu to 1.24 μm at 10 vol% reinforcement. The 3 vol% Ti₃C₂T_x@Ag/Cu composite exhibited the best strength–ductility balance, with an ultimate tensile strength of 288.5 MPa and an elongation of 41.8%, compared with 255.3 MPa and 37.6% for pure Cu, respectively. The hardness increased continuously from 48 to 116 HBW, whereas thermal conductivity showed a non-monotonic dependence on reinforcement content. Ti₃C₂T_x@Ag produced only a modest change in the average friction coefficient but markedly improved wear resistance; the wear rate decreased from 21.24 × 10⁻⁵ mm³·(N·m)⁻¹ for pure Cu to 6.29 × 10⁻⁵ mm³·(N·m)⁻¹ at 10 vol%, corresponding to a 70.4% reduction. Worn-surface, wear-debris, and cross-sectional observations indicate that the improved wear resistance is mainly associated with suppressed cracking and large-scale material spalling, while friction-induced mechanical mixing and oxidation may provide an additional contribution. These results demonstrate that Ag-decorated Ti₃C₂T_x is an effective reinforcement for jointly regulating the mechanical, thermal, and tribological behavior of Cu composites.</div></div>","PeriodicalId":18727,"journal":{"name":"Materials Characterization","volume":"240 ","pages":"Article 117120"},"PeriodicalIF":6.2,"publicationDate":"2026-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149199431","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Ultralow-Cr2O3-doped CuAlO2 with high infrared emissivity and trace leachable Cr(VI) for energy-saving","authors":"Xin Wang,&nbsp;Shaobai Sang,&nbsp;Ankang Lu,&nbsp;Qinghu Wang,&nbsp;Yawei Li,&nbsp;Tianbin Zhu,&nbsp;Heng Wang","doi":"10.1016/j.matchar.2026.117151","DOIUrl":"10.1016/j.matchar.2026.117151","url":null,"abstract":"<div><div>Cr₂O₃ doping has been reported to improve the high-temperature phase stability of CuAlO₂ up to 1600 °C, but the possible formation of hexavalent chromium species remains a concern. In this study, an ultralow-Cr-input strategy was proposed by regulating the Cr₂O₃ addition from 0 to 0.1 mol, and the formation, phase transformation and microstructure evolution of CuAlO₂ phase were discussed. The results show that only a small amount of CuAlO₂ was present at a Cr₂O₃ doping content of 0.01 mol. When the Cr₂O₃ content reached 0.025 mol, CuAlO₂ became the dominant phase, and further increasing the Cr₂O₃ content to 0.05 and 0.1 mol retained the same phase composition. Density functional theory calculations of the Cr-substitution formation energies were used as qualitative indicators. In addition, Cr₂O₃ doping induced lattice vibrational absorption and free-carrier transition absorption, thereby enhancing the infrared emissivity. The sample doped with 0.025 mol Cr₂O₃ exhibited the best overall infrared radiation performance, with an emissivity of 0.887 in the near-infrared region and 0.841 in the mid-infrared region at room temperature. At 800, 1000, and 1200 °C, the near- and mid-band emissivity remained above 0.7, demonstrating strong broadband infrared radiation characteristics. After thermal cycling 20/40 h at 1600 °C, CuAlO₂ remained the dominant phase and high emissivity was retained. The average leachable Cr(VI) concentrations were 0.8, 1.1, 1.3, and 1.8 ppm for the samples doped with 0.01, 0.025, 0.05 mol and 0.1 mol, all values were below the EU standard.</div></div>","PeriodicalId":18727,"journal":{"name":"Materials Characterization","volume":"240 ","pages":"Article 117151"},"PeriodicalIF":6.2,"publicationDate":"2026-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149199183","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Investigation of the impact fracture behavior of in-situ TiC particle-reinforced high-entropy alloy composite coatings through experiments and molecular dynamics simulations","authors":"Jian Gao,&nbsp;Zun Wang,&nbsp;Xiang Kong,&nbsp;Qingchen Meng,&nbsp;Yuan Qin,&nbsp;Ming Huang,&nbsp;Sen Yang","doi":"10.1016/j.matchar.2026.117123","DOIUrl":"10.1016/j.matchar.2026.117123","url":null,"abstract":"<div><div>To enhance the overall mechanical performance of Co-free AlCr_1.75CuFeNi₂ high-entropy alloy (HEA) coating, in-situ TiC particle-reinforced AlCr_1.75CuFeNi₂ HEA composite coatings were fabricated by laser cladding with controlled (Ti + C) additions. The effects of TiC content on the microstructural evolution, hardness, and impact fracture behavior of the coatings were systematically investigated through a combination of experimental characterization and molecular dynamics (MD) simulations. The results show that the in-situ TiC particles significantly refine the dendritic microstructure and promote the formation of an interconnected BCC/B2 spinodal structure in the interdendritic regions. The average grain size decreases from 29.3 μm to 12.9 μm, while the average microhardness value increases from 384.3 HV_1.0 to 497.3 HV_1.0. Charpy impact tests reveal that excessive TiC particles deteriorate impact toughness owing to stress concentration and interfacial debonding, whereas moderate TiC contents maintain relatively high impact energy absorption. MD simulations demonstrate that TiC particles impede dislocation motion through an Orowan bypass mechanism, induce dislocation pile-up, and promote crack deflection. In addition, the high-density BCC/B2 spinodal structure effectively alters crack propagation paths, resulting in enhanced crack-growth resistance and progressive fracture behavior. The combined experimental and simulation results reveal a multiscale synergistic strengthening mechanism involving grain-refinement strengthening at the micrometer scale, strengthening by uniformly dispersed fine in-situ synthesized TiC particles at the submicrometer scale, and energy dissipation associated with high-density disordered/ordered phase interfaces at the nanometer scale. The in-situ TiC particle-reinforced composite coatings achieve an increased strengthening effect while maintaining relatively high impact energy absorption, thereby alleviating the strength-toughness trade-off.</div></div>","PeriodicalId":18727,"journal":{"name":"Materials Characterization","volume":"240 ","pages":"Article 117123"},"PeriodicalIF":6.2,"publicationDate":"2026-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149199353","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}