Intermetallics最新文献

{"title":"The effects of temperature and pressure on the hydrogen decrepitation and hydrogen desorption of Sm2TM17 sintered magnets","authors":"J. Griffiths ,&nbsp;O.P. Brooks ,&nbsp;G. Subramanian ,&nbsp;V. Kozak ,&nbsp;D. Brown ,&nbsp;A. Campbell ,&nbsp;A. Lambourne ,&nbsp;R.S. Sheridan","doi":"10.1016/j.intermet.2025.108831","DOIUrl":"10.1016/j.intermet.2025.108831","url":null,"abstract":"<div><div>This study investigated the impact of hydrogen pressure and processing temperature on the hydrogen decrepitation of Sm₂TM₁₇ sintered magnets (where TM = Co, Fe, Cu and Zr). Sm and Co are ‘critical elements’, hence there is interest in recycling these materials from end-of-life applications such as surface mounted permanent magnet motors and actuators. Hydrogen Decrepitation (HD) is a potential recycling technology, but the effect of different processing parameters has yet to be fully explored. Three commercial grades of Sm₂TM₁₇ sintered magnets with different compositions and microstructures were subjected to HD treatments over 72 h, at hydrogen pressures of 2 and 18 bar and temperatures between 25 and 300 °C. The resulting powders were characterised to assess their particle size and morphology, hydrogen content and degassing behaviour.</div><div>Thermal activation temperatures of 100–150 °C allowed for significant decrepitation to be observed across all Sm₂TM₁₇ compositions at both 2 and 18 bar pressures. Degassing analysis showed that all decrepitated powders examined released hydrogen in a single step, with peak hydrogen desorption occurring between 200 and 260 °C. At HD temperatures of 300 °C the reaction ceased as degassing took precedence over hydrogen absorption. Particle size analysis indicated that adjusting HD processing parameters altered powder size greatly, e.g. increasing temperature increased particle size whereas increasing pressure decreased particle size. The sample with the smallest cell size, greatest Cu and Zr and lowest Fe content absorbed the least amount of hydrogen. It also generated the coarsest powder and degassed at the lowest temperatures. This has been linked to this sample having less of the main interstitial hydride forming 2:17 rhombohedral phase found in the magnet nanostructure.</div></div>","PeriodicalId":331,"journal":{"name":"Intermetallics","volume":"184 ","pages":"Article 108831"},"PeriodicalIF":4.3,"publicationDate":"2025-05-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144107508","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":"The influence of chromium on the changes in phase constitution and electrical properties of amorphous Co73-xFe4CrxSi12B11 microwires during crystallization","authors":"Gennady N. Elmanov ,&nbsp;Ilya V. Kozlov ,&nbsp;Aida E. Sarakueva ,&nbsp;Vladimir I. Odintsov ,&nbsp;Margarita N. Churyukanova ,&nbsp;Sergey A. Gudoshnikov","doi":"10.1016/j.intermet.2025.108848","DOIUrl":"10.1016/j.intermet.2025.108848","url":null,"abstract":"<div><div>The influence of chromium on the crystallization processes (temperature and thermal effect of two crystallization stages, as well as the nature of phase composition change during crystallization) of amorphous Co_{73-<em>x</em>}Fe₄Cr_<em>x</em>Si₁₂B₁₁ (<em>x</em> = 0, 2, 4) alloys obtained in the form of microwires in a glass shell was studied. It was shown that if at the 1st crystallization stage of alloys with chromium there is a simultaneous precipitation of two crystalline phases (HCP phase of a solid solution based on cobalt and BCC-phase of Co₂Si) leading to the formation of a lamellar structure, then in the absence of chromium, only the BCC-phase is initially released. The influence of chromium on the increase in the activation energy of the 1st crystallization stage was determined. It was shown that at the 2nd crystallization stage the presence of chromium stabilizes the HCP-Co and Co₂₃B₆ phases. It is also shown that an increase in the Cr concentration from 0 to 4 at.% increases the specific electrical resistance ρ_25 °C of the alloys in the crystalline state from 0.68 ∙ 10⁻⁶ to 1.18 ∙ 10⁻⁶ Ohm ∙ m and simultaneously reduces the thermal coefficient of electrical resistance by 4 times. Based on the resistive measurement data, the Curie temperatures of the magnetic phases formed during crystallization were estimated. Comparison of the data obtained using the DSC and XRPD methods with the results of changes in electrical resistance during crystallization made it possible to interpret the results of resistive measurements and to demonstrate the efficiency of this simple method for studying the crystallization process of amorphous alloys.</div></div>","PeriodicalId":331,"journal":{"name":"Intermetallics","volume":"184 ","pages":"Article 108848"},"PeriodicalIF":4.3,"publicationDate":"2025-05-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144098537","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":"Additive manufacturing of Ti/Zr/Mo/Al lightweight refractory complex concentrated Alloy: Integrated computational material engineering approach","authors":"Madhavan Radhakrishnan ,&nbsp;Jitesh Kumar ,&nbsp;KN Chaithanya Kumar ,&nbsp;Sudip Kumar Sarkar ,&nbsp;Krishna Kamlesh Verma ,&nbsp;Selvamurugan Palaniappan ,&nbsp;Saikumar Dussa ,&nbsp;Shashank Sharma ,&nbsp;Narendra B. Dahotre","doi":"10.1016/j.intermet.2025.108835","DOIUrl":"10.1016/j.intermet.2025.108835","url":null,"abstract":"<div><div>Refractory complex concentrated alloys (RCCAs) comprising refractory metals, are potential candidates for high-temperature applications. The compositional screening of a suitable alloy is very challenging due to the vast compositional space of complex concentrated alloys (CCAs). To address this issue, an integrated computational materials engineering (ICME) framework consisting of detailed CALPHAD (CALculation of PHase Diagram) modeling was adopted to design non-equiatomic Ti/Zr/Mo/Al CCAs. The one-axis equilibrium diagram reveals that Ti₄₀Zr₄₀Mo₁₀Al₁₀ (at. %) exhibits predominantly a single-phase BCC structure over the wide temperature range (860–1660 °C). The alloy was fabricated using laser based directed energy deposition technique. The detailed characterization of as-printed samples revealed the formation of equiaxed grains along build direction with single phase BCC microstructure. Due to the high fraction of porosities, the as-printed alloy was subjected to hot isostatic pressing treatment that resulted in near complete densification of the printed alloy and led to the precipitation of A₃B type precipitates and B2 nano clusters as evidenced by TEM and APT techniques. Finite element (FE) based multilayer and multitrack thermokinetic model approach was considered to seek an insight into the grain morphology evolution during additive manufacturing of these alloys.</div></div>","PeriodicalId":331,"journal":{"name":"Intermetallics","volume":"184 ","pages":"Article 108835"},"PeriodicalIF":4.3,"publicationDate":"2025-05-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144098538","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":"High-temperature tensile and fatigue properties of Ti-48Al-2Cr-2Nb alloy additively manufactured via twin-wire directed energy deposition-arc","authors":"Wenlu Zhou ,&nbsp;Chen Shen ,&nbsp;Lin Wang ,&nbsp;Ying Li ,&nbsp;Ting Zhang ,&nbsp;Jianwen Xin ,&nbsp;Yuhan Ding ,&nbsp;Danqi Zhang ,&nbsp;Yuelong Zhang ,&nbsp;Fang Li ,&nbsp;Xueming Hua","doi":"10.1016/j.intermet.2025.108833","DOIUrl":"10.1016/j.intermet.2025.108833","url":null,"abstract":"<div><div>Recently, additive manufacturing of titanium aluminide has attracted widespread attention. Since titanium aluminide is an ideal structure material for high-temperature, corresponding mechanical properties are of great significance. In present work, tensile properties from 25 °C to 1050 °C and fatigue properties at 650 °C were examined for the first time on twin-wire directed energy deposition-arc (TW-DED-arc) manufactured Ti-48Al-2Cr-2Nb (TiAl-4822) alloy. Importantly, fracture characteristics and deformation mechanisms were systematically investigated. Similar with extensively investigated titanium aluminide, TW-DED-arc manufactured TiAl-4822 alloy generally tends to decrease strength while increase elongation versus temperature during tensile process. Meanwhile, anomalous increase of strength is detected at 750 °C, and brittle-to-ductile transition temperature (BDTT) is around 850 °C. At 25 °C and 550 °C, γ/α₂ lamellar interface and lamellar colony boundary as well as special microstructures are weak positions and susceptible to microcracking, and mechanical twining dominates deformation mode. By comparison, in temperature range of 650 °C–950 °C, γ/α₂ interface and colony boundary are weaker, while deformation mechanism shifts to mechanical twinning and dislocation slip. Moreover, dynamic recrystallization (DRX) starts at 850 °C and further affects tensile behaviors, especially at 1050 °C. The fatigue limit (10⁷ cycles) at 650 °C is approximately 335 MPa, ratio of which to tensile strength is calculated to be 0.71, indicating good fatigue resistance of as-manufactured TiAl-4822 alloy. Irrespective of stress level, crack prefer to initiate and propagate at γ/α₂ interface and colony boundary. Both mechanical twining and dislocation slip are activated during fatigue process, but their morphologies vary with stress level. In sum, these findings provide a valuable reference for mechanical properties of additively manufactured titanium aluminide.</div></div>","PeriodicalId":331,"journal":{"name":"Intermetallics","volume":"184 ","pages":"Article 108833"},"PeriodicalIF":4.3,"publicationDate":"2025-05-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144071131","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-driven property evolution in metal additive manufactured nickel alloy","authors":"R. Raghu ,&nbsp;P. Chandramohan ,&nbsp;D. Pradeesh kumar ,&nbsp;Amar Singh","doi":"10.1016/j.intermet.2025.108834","DOIUrl":"10.1016/j.intermet.2025.108834","url":null,"abstract":"<div><div>The laser Powder Bed Fusion (LPBF) process is vital for aerospace sector to produce components with intricate geometry for better performance. In the present study, the nickel-based superalloy CM247LC was manufactured through LPBF. Microscopically, alloy revealed the presence of carbides. In the longitudinal section, Electron Backscatter Diffraction (EBSD) exposed elongated grains and in transverse section, equiaxed clusters. Rate of cooling during solidification was calculated to be approximately 10⁶ K/s. Yield strength of the samples found higher compared to the previous research. Sources of higher strength are interpreted as higher precipitate concentrations, dislocation density, finer cellular structure, and γ′ inside cells.</div></div>","PeriodicalId":331,"journal":{"name":"Intermetallics","volume":"184 ","pages":"Article 108834"},"PeriodicalIF":4.3,"publicationDate":"2025-05-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144071132","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":"Vacuum plasma sprayed AlCoCrFeNi high-entropy alloy bond Coating: Vacuum heat-treatment, microstructure evolution and oxidation behavior analysis","authors":"Hanfang Zhang ,&nbsp;Xiao Zhang ,&nbsp;Jun Zhang ,&nbsp;Mingming Pan","doi":"10.1016/j.intermet.2025.108836","DOIUrl":"10.1016/j.intermet.2025.108836","url":null,"abstract":"<div><div>The AlCoCrFeNi high-entropy alloy (HEA) bond coating is fabricated using vacuum plasma spray (VPS) technology, followed by a vacuum heat treatment (VHT) at 1050 °C for 5 h. This study rigorously investigates the effects of the VHT process on the microstructural evolution and oxidation resistance of the AlCoCrFeNi coating. The experimental findings indicate that both the as-sprayed and heat-treated coatings develop thermally grown oxide (TGO) layers predominantly composed of α-Al₂O₃ under oxidation conditions up to 1000 °C. Notably, the VHT-treated coating exhibits enhanced oxidation resistance, showing a 12.3 % reduction in TGO layer thickness after 50 h of oxidation at 1000 °C, compared to its untreated counterpart. This improvement is attributed to the microstructural changes during VHT, including grain coarsening and a decrease in grain boundary density, which collectively reduce the diffusion of Al ions outward. Additionally, phase analysis demonstrates that the AlCoCrFeNi coating transitions from an initial BCC structure to a BCC + FCC + σ-phase following vacuum heat treatment. The emergence of the FCC phase leads to a 23 % reduction in coating hardness (from 506.1 HV to 388.8 HV), which aids in stress relaxation at the TGO/coating interface and reduces the likelihood of crack initiation. Overall, this research, which offers a simple and effective method for enhancing the oxidation resistance of high entropy alloys.</div></div>","PeriodicalId":331,"journal":{"name":"Intermetallics","volume":"184 ","pages":"Article 108836"},"PeriodicalIF":4.3,"publicationDate":"2025-05-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144069445","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":"Characterization of hot deformation of FeCoCrNiAl0.1 high entropy alloy: 3D processing maps, FEM numerical simulation and microstructure evolution","authors":"Bo Li ,&nbsp;Xiuyu Yu ,&nbsp;Zhicheng Huang ,&nbsp;Zhaojie Chu ,&nbsp;Han Yang ,&nbsp;Qinyi Zhu ,&nbsp;Xicong Ye ,&nbsp;Dong Fang ,&nbsp;Youlu Yuan","doi":"10.1016/j.intermet.2025.108821","DOIUrl":"10.1016/j.intermet.2025.108821","url":null,"abstract":"<div><div>To investigate the hot deformation and dynamic recrystallization (DRX) behavior of FeCoCrNiAl_0.1 high-entropy alloy (HEA), hot compression tests were conducted under varying temperatures range of 950–1100 °C with strain rates range of 0.001 and 1 s⁻¹. FeCoCrNiAl_0.1 HEA exhibit distinct DRX characteristics, synergistically controlled by dynamic recovery (DRV) and DRX. The hot processing map indicates that the studied alloy exhibits an optimal hot processing window of 1000–1100 °C/0.001–0.02 s⁻¹. According to finite element model (FEM), DRX distribution is temperature and strain-rate-dependent. The DRX region expands radially from core to peripheral with increasing temperature or decreasing strain rate. Microstructural evolution analysis reveals that the studied alloy exhibits pronounced DRV and DRX characteristics during hot deformation. DRX primarily proceeds through Continuous Dynamic Recrystallization (CDRX) driven by subgrain rotation and Discontinuous Dynamic Recrystallization (DDRX) through grain boundary bulging nucleation. As strain rate decreases or temperature increases, the studied alloy exhibits a grain coarsening and substantial dislocation density reduction. The grain orientation evolves from the typical R texture {134}&lt;211&gt; to the Cube texture {001}&lt;100&gt;, and this texture transition facilitates the progression of DRX.</div></div>","PeriodicalId":331,"journal":{"name":"Intermetallics","volume":"183 ","pages":"Article 108821"},"PeriodicalIF":4.3,"publicationDate":"2025-05-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143948739","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":"Bauschinger effect on high entropy alloy under cyclic deformation","authors":"Hoang-Giang Nguyen ,&nbsp;Sheng-Joue Young ,&nbsp;Thanh-Dung Le ,&nbsp;Thi-Nhai Vu ,&nbsp;Te-Hua Fang","doi":"10.1016/j.intermet.2025.108830","DOIUrl":"10.1016/j.intermet.2025.108830","url":null,"abstract":"<div><div>This study employs molecular dynamics (MD) simulations to examine materials with comparable tension-compression behavior but markedly different cyclic fatigue performances. The findings reveal that the cyclic fatigue properties of AlCoCrCuFeNi high-entropy alloys (HEAs) are primarily governed by microscopic deformation mechanisms, particularly dislocation slip modes, which subtly affect initial work hardening. However, the slight initial differences in work hardening affected by the butterfly and Bauschinger effects gradually accumulate and intensify with repeated fatigue cycling. As the number of loading cycles increases, β-asymmetry steadily declines. Interactions between partial dislocations and stacking faults (SFs) at lower temperatures disrupt the lattice structure and impede dislocation reversal, thereby diminishing the Bauschinger effect. This mechanism contributes to marked variations in fatigue life and cyclic stress response.</div></div>","PeriodicalId":331,"journal":{"name":"Intermetallics","volume":"183 ","pages":"Article 108830"},"PeriodicalIF":4.3,"publicationDate":"2025-05-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144068775","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 microstructure evolution and nanoindentation hardness of an oxygen-doped Ti35Zr35Hf20Nb10 nanograined multi-principal element alloy","authors":"Rong Huang ,&nbsp;Zongde Kou ,&nbsp;Song Tang ,&nbsp;Shimao Lv ,&nbsp;Gerhard Wilde ,&nbsp;Si Lan ,&nbsp;Tao Feng","doi":"10.1016/j.intermet.2025.108826","DOIUrl":"10.1016/j.intermet.2025.108826","url":null,"abstract":"<div><div>In this study, an oxygen-doped nominal component of (Ti₃₅Zr₃₅Hf₂₀Nb₁₀)₉₈O₂ nanograined multi-principal element alloy (NG-MPEA) with an average grain size of about 50 nm was synthesized via inert gas condensation (IGC). Moreover, the mechanical properties and microstructural evolution of the alloys were systematically investigated. The as-prepared samples (as-IGC) are composed of two phases with body-centered cubic (bcc) and hexagonal close-packed (hcp) structures. The samples were annealed to regulate the microstructure. The results demonstrate that when annealed at temperatures below 450 °C, the dual-phase structure composed of bcc and hcp phases was maintained. However, when annealed at 650 °C, a phase transformation of bcc to nano-sized ordered ω’ were observed. The nanoindentation hardness of the NG-MPEA increases from 4.5 GPa to 6.3 GPa after annealing at 450 °C and further increases to 7.6 GPa after annealing at 650 °C. Compared with the as-IGC state, the hardness increased by 69 %. The relationship between microstructure evolution and nanoindentation hardness was further discussed. This work provides an effective approach for enhancing the hardness of bulk NG-MPEAs by adjusting their microstructure.</div></div>","PeriodicalId":331,"journal":{"name":"Intermetallics","volume":"183 ","pages":"Article 108826"},"PeriodicalIF":4.3,"publicationDate":"2025-05-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143948738","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":"Corrosion mechanism of CrMnFeCoNi high entropy alloy in nitric acid solution","authors":"Feng Han ,&nbsp;Chunyang Li ,&nbsp;Chenghao Li ,&nbsp;Jiacai Wang ,&nbsp;Chaobo Xia ,&nbsp;Xiubo Li ,&nbsp;Long Xue ,&nbsp;Caimei Wang","doi":"10.1016/j.intermet.2025.108822","DOIUrl":"10.1016/j.intermet.2025.108822","url":null,"abstract":"<div><div>The corrosion behavior and passive film characteristics of CrMnFeCoNi high entropy alloy (HEA) in HNO₃ solution (0.1 M, 1 M, 4 M and 6 M) was investigated. The electrochemical test results demonstrated enhanced corrosion resistance with increasing HNO₃ concentration, evidenced by higher corrosion potential, lower passivation current density, and larger impedance modulus value. XPS and finite element analysis confirmed that the improved corrosion resistance in 6 M HNO₃ was attributed to a Cr₂O₃-rich passive film (22.5 %), formed via autocatalytic redox reactions and stabilized by Mn²⁺ inhibiting Cr(III) oxidation.</div></div>","PeriodicalId":331,"journal":{"name":"Intermetallics","volume":"183 ","pages":"Article 108822"},"PeriodicalIF":4.3,"publicationDate":"2025-05-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143942355","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}