Pub Date : 2025-12-09DOI: 10.1016/j.intermet.2025.109124
Zhanxuan Wang , Heling Zheng , Mingyang Wang , Xintian Li , Xiancheng Li , Zhengkun Li , Zhonghua Du , Lizhi Xu
This study comprehensively characterizes the dynamic mechanical response of the Zr42Ti15Nb20Ta20Al3(at.%) refractory high-entropy alloy (RHEA) spanning a strain rate spectrum from 0.001 to 5500 s−1. A significant strain-rate hardening effect, where the yield strength surged from 1166 MPa under quasi-static loading to 2017 MPa in the dynamic regime. Microstructural examinations indicate a fundamental shift in the deformation mode: while dislocation slip dominates at lower rates, adiabatic shear bands (ASBs) precipitate failure under high-velocity impact. Based on these empirical findings, the Johnson-Cook constitutive and damage parameters were calibrated. The model was validated through ballistic experiment, and the simulation was in excellent agreement with the experimental observations. These results highlight the potential of this RHEA for next-generation warhead applications.
{"title":"Strain rate sensitivity and dynamic constitutive response of a Zr42Ti15Nb20Ta20Al3 refractory high-entropy alloy","authors":"Zhanxuan Wang , Heling Zheng , Mingyang Wang , Xintian Li , Xiancheng Li , Zhengkun Li , Zhonghua Du , Lizhi Xu","doi":"10.1016/j.intermet.2025.109124","DOIUrl":"10.1016/j.intermet.2025.109124","url":null,"abstract":"<div><div>This study comprehensively characterizes the dynamic mechanical response of the Zr<sub>42</sub>Ti<sub>15</sub>Nb<sub>20</sub>Ta<sub>20</sub>Al<sub>3</sub>(at.%) refractory high-entropy alloy (RHEA) spanning a strain rate spectrum from 0.001 to 5500 s<sup>−1</sup>. A significant strain-rate hardening effect, where the yield strength surged from 1166 MPa under quasi-static loading to 2017 MPa in the dynamic regime. Microstructural examinations indicate a fundamental shift in the deformation mode: while dislocation slip dominates at lower rates, adiabatic shear bands (ASBs) precipitate failure under high-velocity impact. Based on these empirical findings, the Johnson-Cook constitutive and damage parameters were calibrated. The model was validated through ballistic experiment, and the simulation was in excellent agreement with the experimental observations. These results highlight the potential of this RHEA for next-generation warhead applications.</div></div>","PeriodicalId":331,"journal":{"name":"Intermetallics","volume":"189 ","pages":"Article 109124"},"PeriodicalIF":4.8,"publicationDate":"2025-12-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145733913","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}
Pub Date : 2025-12-08DOI: 10.1016/j.intermet.2025.109118
Daoguang He , Xiao-yang Chen , Y.C. Lin , Han Xie , Baishan Chen
The evolution features of the texture, substructure and grain structure for a C276 superalloy in the dual-stages high-temperature compression with instantaneous strain rates are revealed. The interacting mechanisms between the pre-precipitation μ phase and dynamic recrystallization (DRX) grains are explored. The experimental results reveal that the formation/development of low-angle-grain-boundaries is progressively promoted with descended compressed temperature or ascended first/second stage strain rate. Whereas DRX grains nucleating and coarsening tendency is inhibited. Three mechanisms, i.e., μ phase stimulated DRX nucleus and discontinuous/continuous DRX, are the dominant DRX nucleation. Besides, the principal components of micro-textures of the C276 superalloy during dual-stages high-temperature compression with instantaneous strain rates are Brass texture, P texture, S texture and Cube texture. The fraction of Cube texture appreciably ascends with the ascended or reduced first/second stage strain rate. Besides, a promoted dislocation-density model considering the interacted impacts among substructure, μ phase and grain structure is established, which enables to be adopted to precisely forecast the variating characteristics of compressed stress and multiple microstructures, i.e., substructures and DRX grain.
{"title":"Microstructural interacting mechanisms and a promoted dislocation-density model for a C276 superalloy with pre-precipitated μ phase in dual-stages high-temperature compression with instantaneous strain rates","authors":"Daoguang He , Xiao-yang Chen , Y.C. Lin , Han Xie , Baishan Chen","doi":"10.1016/j.intermet.2025.109118","DOIUrl":"10.1016/j.intermet.2025.109118","url":null,"abstract":"<div><div>The evolution features of the texture, substructure and grain structure for a C276 superalloy in the dual-stages high-temperature compression with instantaneous strain rates are revealed. The interacting mechanisms between the pre-precipitation μ phase and dynamic recrystallization (DRX) grains are explored. The experimental results reveal that the formation/development of low-angle-grain-boundaries is progressively promoted with descended compressed temperature or ascended first/second stage strain rate. Whereas DRX grains nucleating and coarsening tendency is inhibited. Three mechanisms, i.e., μ phase stimulated DRX nucleus and discontinuous/continuous DRX, are the dominant DRX nucleation. Besides, the principal components of micro-textures of the C276 superalloy during dual-stages high-temperature compression with instantaneous strain rates are Brass texture, P texture, S texture and Cube texture. The fraction of Cube texture appreciably ascends with the ascended <span><math><mrow><mi>T</mi></mrow></math></span> or reduced first/second stage strain rate. Besides, a promoted dislocation-density model considering the interacted impacts among substructure, μ phase and grain structure is established, which enables to be adopted to precisely forecast the variating characteristics of compressed stress and multiple microstructures, i.e., substructures and DRX grain.</div></div>","PeriodicalId":331,"journal":{"name":"Intermetallics","volume":"189 ","pages":"Article 109118"},"PeriodicalIF":4.8,"publicationDate":"2025-12-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145733923","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}
Pub Date : 2025-12-07DOI: 10.1016/j.intermet.2025.109123
O. Zakir , O. Guler , R. Idouhli , M. Aklalouch , B. Dikici , M.E. Khadiri , A. Abouelfida , V. Selen , T. Şimşek
In this study, the photocatalytic performance of NbTiZrW-based high-entropy alloys (HEAs) with Hf, Mo, and Ta additions was investigated. The alloys were synthesized by mechanical alloying for 120 h under a high-purity Ar atmosphere to prevent oxidation. The photocatalytic activity of the samples was evaluated based on the degradation of methylene blue (MB) under UV irradiation. Structural and chemical characterizations were performed using energy-dispersive spectroscopy (EDS), X-ray diffraction (XRD), scanning electron microscopy (SEM), and X-ray photoelectron spectroscopy (XPS). The results showed that MB removal by adsorption reached 22.96 % for NbTiZrWHf, 21.90 % for NbTiZrWTa, and 47.01 % for NbTiZrWMo. The incorporation of Mo into the NbTiZrW alloy was found to enhance electrostatic interactions between MB molecules and the alloy surface. Upon UV irradiation, the degradation efficiency increased significantly, reaching 32.84 % for NbTiZrWHf, 82.02 % for NbTiZrWTa, and 46.13 % for NbTiZrWMo within 3 h. The improved performance of the NbTiZrWHf alloy was attributed to its low particle size, which provided a larger number of active sites for photocatalytic activity, as confirmed by SEM analysis.
{"title":"Exploring the photocatalytic potential of NbTiZrW-based high-entropy alloys with Hf/Mo/Ta additions: Influence of alloying elements on their structural and photocatalytic performance","authors":"O. Zakir , O. Guler , R. Idouhli , M. Aklalouch , B. Dikici , M.E. Khadiri , A. Abouelfida , V. Selen , T. Şimşek","doi":"10.1016/j.intermet.2025.109123","DOIUrl":"10.1016/j.intermet.2025.109123","url":null,"abstract":"<div><div>In this study, the photocatalytic performance of NbTiZrW-based high-entropy alloys (HEAs) with Hf, Mo, and Ta additions was investigated. The alloys were synthesized by mechanical alloying for 120 h under a high-purity Ar atmosphere to prevent oxidation. The photocatalytic activity of the samples was evaluated based on the degradation of methylene blue (MB) under UV irradiation. Structural and chemical characterizations were performed using energy-dispersive spectroscopy (EDS), X-ray diffraction (XRD), scanning electron microscopy (SEM), and X-ray photoelectron spectroscopy (XPS). The results showed that MB removal by adsorption reached 22.96 % for NbTiZrWHf, 21.90 % for NbTiZrWTa, and 47.01 % for NbTiZrWMo. The incorporation of Mo into the NbTiZrW alloy was found to enhance electrostatic interactions between MB molecules and the alloy surface. Upon UV irradiation, the degradation efficiency increased significantly, reaching 32.84 % for NbTiZrWHf, 82.02 % for NbTiZrWTa, and 46.13 % for NbTiZrWMo within 3 h. The improved performance of the NbTiZrWHf alloy was attributed to its low particle size, which provided a larger number of active sites for photocatalytic activity, as confirmed by SEM analysis.</div></div>","PeriodicalId":331,"journal":{"name":"Intermetallics","volume":"189 ","pages":"Article 109123"},"PeriodicalIF":4.8,"publicationDate":"2025-12-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145733916","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}
Pub Date : 2025-12-06DOI: 10.1016/j.intermet.2025.109125
Z.B. Li , J.M. Yuan , Q. Wang , D. Ding , L. Xia
By replacing a small amount of Fe with Co in the Fe88Pr10Al2 amorphous alloy, we obtained Fe86Co2Pr10Al2 amorphous ribbons with excellent magnetocaloric properties near 313 K. The microstructure, glass formability, magnetic and magnetocaloric properties of the Co-doped metallic glass were studied and compared to those of the Co-free metallic glass. It was found that the fully amorphous Fe86Co2Pr10Al2 ribbon exhibits remarkable magnetocaloric properties, including a Curie temperature (Tc) of 313 K, a notably high magnetic entropy change peak (−ΔSmpeak, ∼4.79 J/(kg × K)) and a refrigerant capacity up to 766 J/kg under 5 T. The mechanism by which the Co substitution affects the magnetic and magnetocaloric properties of the Fe88Pr10Al2 amorphous alloy was investigated.
{"title":"Achieving higher Curie temperature and magnetic entropy change by minor Co substitution for Fe in a Fe88Pr10Al2 amorphous alloy","authors":"Z.B. Li , J.M. Yuan , Q. Wang , D. Ding , L. Xia","doi":"10.1016/j.intermet.2025.109125","DOIUrl":"10.1016/j.intermet.2025.109125","url":null,"abstract":"<div><div>By replacing a small amount of Fe with Co in the Fe<sub>88</sub>Pr<sub>10</sub>Al<sub>2</sub> amorphous alloy, we obtained Fe<sub>86</sub>Co<sub>2</sub>Pr<sub>10</sub>Al<sub>2</sub> amorphous ribbons with excellent magnetocaloric properties near 313 K. The microstructure, glass formability, magnetic and magnetocaloric properties of the Co-doped metallic glass were studied and compared to those of the Co-free metallic glass. It was found that the fully amorphous Fe<sub>86</sub>Co<sub>2</sub>Pr<sub>10</sub>Al<sub>2</sub> ribbon exhibits remarkable magnetocaloric properties, including a Curie temperature (<em>T</em><sub><em>c</em></sub>) of 313 K, a notably high magnetic entropy change peak (−<em>ΔS</em><sub><em>m</em></sub><sup><em>peak</em></sup>, ∼4.79 J/(kg × K)) and a refrigerant capacity up to 766 J/kg under 5 T. The mechanism by which the Co substitution affects the magnetic and magnetocaloric properties of the Fe<sub>88</sub>Pr<sub>10</sub>Al<sub>2</sub> amorphous alloy was investigated.</div></div>","PeriodicalId":331,"journal":{"name":"Intermetallics","volume":"189 ","pages":"Article 109125"},"PeriodicalIF":4.8,"publicationDate":"2025-12-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145733925","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}
Pub Date : 2025-12-06DOI: 10.1016/j.intermet.2025.109122
Xiaohui Qin , Liran Huang , Pei Wang , Wentao Yan , Zhiqiang Fu
We report the fabrication of a L12-strengthened high-entropy alloy (HEA), Ni27.7Cr24Co23.5Fe15.7Mo1.6Al3Ti4.5 (at. %), using binder jet 3D printing (BJ3DP), consisting of printing and subsequent sintering. The resulting alloy exhibits high strength and corrosion resistance. This study systematically investigates the interdependence among processing parameters, microstructural evolution, and resulting properties. Optimal printing parameters (50 μm layer thickness, 50 % binder saturation, 3 mm/s spreading speed) yielded a green density of ∼58 %. Subsequent sintering at 1280 °C for 4 h achieved the highest relative density of ∼99.2 %. The microstructural evolution during sintering governed L12 precipitation and porosity, which in turn dictated the mechanical properties and corrosion resistance. Superior performance was achieved after sintering at 1280 °C. This condition produced enhanced densification and refined L12 precipitates, resulting in a yield strength of ∼726 MPa, ultimate tensile strength of ∼1112 MPa, and elongation of ∼16.5 %. Conversely, sintering at 1290 °C caused partial melting and precipitate coarsening, which degraded both strength and corrosion resistance. Electrochemical tests in 3.5 wt% NaCl solution confirmed the optimal corrosion resistance of the 1280 °C sample, which exhibited a pitting potential (∼0.97 VSCE) significantly higher than that of 316L stainless steel. In contrast, samples sintered below 1280 °C showed excessive porosity, while those above 1290 °C exhibited microstructural instability, both leading to severe pitting and galvanic corrosion. These results establish clear process–microstructure–property relationships for BJ3DP-fabricated HEAs and demonstrate a viable pathway for tailoring multifunctional performance through controlled processing.
{"title":"Understanding the process-microstructure-property relationships in a L12-strengthened high-entropy alloy fabricated by binder jet 3D printing","authors":"Xiaohui Qin , Liran Huang , Pei Wang , Wentao Yan , Zhiqiang Fu","doi":"10.1016/j.intermet.2025.109122","DOIUrl":"10.1016/j.intermet.2025.109122","url":null,"abstract":"<div><div>We report the fabrication of a L1<sub>2</sub>-strengthened high-entropy alloy (HEA), Ni<sub>27.7</sub>Cr<sub>24</sub>Co<sub>23.5</sub>Fe<sub>15.7</sub>Mo<sub>1.6</sub>Al<sub>3</sub>Ti<sub>4.5</sub> (at. %), using binder jet 3D printing (BJ3DP), consisting of printing and subsequent sintering. The resulting alloy exhibits high strength and corrosion resistance. This study systematically investigates the interdependence among processing parameters, microstructural evolution, and resulting properties. Optimal printing parameters (50 μm layer thickness, 50 % binder saturation, 3 mm/s spreading speed) yielded a green density of ∼58 %. Subsequent sintering at 1280 °C for 4 h achieved the highest relative density of ∼99.2 %. The microstructural evolution during sintering governed L1<sub>2</sub> precipitation and porosity, which in turn dictated the mechanical properties and corrosion resistance. Superior performance was achieved after sintering at 1280 °C. This condition produced enhanced densification and refined L1<sub>2</sub> precipitates, resulting in a yield strength of ∼726 MPa, ultimate tensile strength of ∼1112 MPa, and elongation of ∼16.5 %. Conversely, sintering at 1290 °C caused partial melting and precipitate coarsening, which degraded both strength and corrosion resistance. Electrochemical tests in 3.5 wt% NaCl solution confirmed the optimal corrosion resistance of the 1280 °C sample, which exhibited a pitting potential (∼0.97 V<sub>SCE</sub>) significantly higher than that of 316L stainless steel. In contrast, samples sintered below 1280 °C showed excessive porosity, while those above 1290 °C exhibited microstructural instability, both leading to severe pitting and galvanic corrosion. These results establish clear process–microstructure–property relationships for BJ3DP-fabricated HEAs and demonstrate a viable pathway for tailoring multifunctional performance through controlled processing.</div></div>","PeriodicalId":331,"journal":{"name":"Intermetallics","volume":"189 ","pages":"Article 109122"},"PeriodicalIF":4.8,"publicationDate":"2025-12-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145682044","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}
Pub Date : 2025-12-06DOI: 10.1016/j.intermet.2025.109121
Siyu Zhou , Cong Zhao , Shuo Wang , Han Xie , Yushi Wang , Xinyu Li , Fei Xing , Zhonggang Sun , Guang Yang
Laser directed energy deposited Inconel 718 alloy typically exhibits coarse columnar grains and Nb/Mo-rich Laves phases, leading to poor strength and plasticity matching. To address this, friction stir processing (FSP) was combined with solution-aging heat treatment for the first time. Results show that FSP refines coarse columnar grains (47 μm) into fine equiaxed grains (2.7 μm) via dynamic recrystallization, while breaking the chain-like Laves phase and reducing its content from 6.1 % to 0.55 %. After heat treatment, static recrystallization occurs in the stir zone, accompanied by annealing twins, with grain size stabilizing at 9.9 μm. The Laves phase is further dissolved to 0.12 %, while a high density of γ′/γ″ strengthening precipitates is formed. This synergistic process enhances both strength and plasticity through grain refinement, precipitation strengthening, and the inhibition of grain boundary migration by annealing twins. Consequently, the material exhibits an excellent strength and plasticity matching, demonstrating a room-temperature tensile strength of 1506 MPa, a yield strength of 1023 MPa, an elongation of 29 %, and a product of strength and plasticity of 43.7 GPa·%.
{"title":"Achieving uniform microstructure and excellent mechanical properties of laser directed energy deposited IN718 via friction stir processing and heat treatment","authors":"Siyu Zhou , Cong Zhao , Shuo Wang , Han Xie , Yushi Wang , Xinyu Li , Fei Xing , Zhonggang Sun , Guang Yang","doi":"10.1016/j.intermet.2025.109121","DOIUrl":"10.1016/j.intermet.2025.109121","url":null,"abstract":"<div><div>Laser directed energy deposited Inconel 718 alloy typically exhibits coarse columnar grains and Nb/Mo-rich Laves phases, leading to poor strength and plasticity matching. To address this, friction stir processing (FSP) was combined with solution-aging heat treatment for the first time. Results show that FSP refines coarse columnar grains (47 μm) into fine equiaxed grains (2.7 μm) via dynamic recrystallization, while breaking the chain-like Laves phase and reducing its content from 6.1 % to 0.55 %. After heat treatment, static recrystallization occurs in the stir zone, accompanied by annealing twins, with grain size stabilizing at 9.9 μm. The Laves phase is further dissolved to 0.12 %, while a high density of γ′/γ″ strengthening precipitates is formed. This synergistic process enhances both strength and plasticity through grain refinement, precipitation strengthening, and the inhibition of grain boundary migration by annealing twins. Consequently, the material exhibits an excellent strength and plasticity matching, demonstrating a room-temperature tensile strength of 1506 MPa, a yield strength of 1023 MPa, an elongation of 29 %, and a product of strength and plasticity of 43.7 GPa·%.</div></div>","PeriodicalId":331,"journal":{"name":"Intermetallics","volume":"189 ","pages":"Article 109121"},"PeriodicalIF":4.8,"publicationDate":"2025-12-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145733924","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}
Pub Date : 2025-12-06DOI: 10.1016/j.intermet.2025.109090
Shih-Hung Lin , Yung-Huang Chang , Yuan-Tsung Chen , Xuan-Ming Su , Wen Chang , Huang-Wei Chang
Amorphous cobalt-iron-gadolinium (Co40Fe40Gd20) thin films with thicknesses of 10 nm–50 nm were deposited on flexible polyethylene terephthalate (PET) and polymethyl methacrylate (PMMA) substrates via direct-current (DC) magnetron sputtering and annealed at 40 °C and 80 °C to investigate the effects of film thickness, annealing temperature, and substrate type on structural, mechanical, electrical, magnetic, and optical properties. X-ray diffraction (XRD) confirmed the films remained amorphous under all conditions, due to the high gadolinium (Gd) content and limited thermal energy below the polymer glass transition temperatures. Atomic force microscopy (AFM) revealed substrate-dependent surface evolution, with PET films showing a decrease in roughness from 5.91 nm to 4.79 nm after 80 °C annealing, whereas PMMA films exhibited minimal roughness change. Surface energy increased with film thickness but decreased slightly upon annealing due to atomic rearrangement. Mechanical properties improved with both thickness and annealing. PET films reached a maximum Young's modulus of 22.58 GPa and hardness of 4.75 Gpa at 50 nm after 80 °C annealing, while PMMA films achieved 15.05 GPa modulus at 50 nm after 40 °C. Electrical measurements showed a significant reduction in sheet resistance from 7261 Ω/sq for as-deposited 10 nm films to 144 Ω/sq for 50 nm films annealed at 80 °C, with enhanced carrier mobility and concentration. Magnetic analysis confirmed in-plane soft magnetic behavior, with minor variations in coercivity (Hc) and saturation magnetization (Ms) influenced by stress relaxation and morphology-induced anisotropy. Magnetic force microscopy (MFM) indicated moderate annealing promoted ordered stripe domains, while higher temperatures induced domain coarsening. Optical characterization revealed transmittance decreased with thickness, reaching 40.68 % and 47.15 % at 10 nm on PET and PMMA at annealing 40 °C, whereas absorbance increased, indicating thickness-dominated optical behavior. These findings demonstrate that controlled annealing and thickness optimization enable precise tuning of surface roughness and multifunctional properties of CoFeGd amorphous films on flexible substrates, supporting their design for advanced flexible spintronic, electronic, and optoelectronic devices.
{"title":"Role of surface roughness in governing the mechanical, electrical, magnetic, and optical properties of amorphous Co40Fe40Gd20 thin films on flexible substrates","authors":"Shih-Hung Lin , Yung-Huang Chang , Yuan-Tsung Chen , Xuan-Ming Su , Wen Chang , Huang-Wei Chang","doi":"10.1016/j.intermet.2025.109090","DOIUrl":"10.1016/j.intermet.2025.109090","url":null,"abstract":"<div><div>Amorphous cobalt-iron-gadolinium (Co<sub>40</sub>Fe<sub>40</sub>Gd<sub>20</sub>) thin films with thicknesses of 10 nm–50 nm were deposited on flexible polyethylene terephthalate (PET) and polymethyl methacrylate (PMMA) substrates via direct-current (DC) magnetron sputtering and annealed at 40 °C and 80 °C to investigate the effects of film thickness, annealing temperature, and substrate type on structural, mechanical, electrical, magnetic, and optical properties. X-ray diffraction (XRD) confirmed the films remained amorphous under all conditions, due to the high gadolinium (Gd) content and limited thermal energy below the polymer glass transition temperatures. Atomic force microscopy (AFM) revealed substrate-dependent surface evolution, with PET films showing a decrease in roughness from 5.91 nm to 4.79 nm after 80 °C annealing, whereas PMMA films exhibited minimal roughness change. Surface energy increased with film thickness but decreased slightly upon annealing due to atomic rearrangement. Mechanical properties improved with both thickness and annealing. PET films reached a maximum Young's modulus of 22.58 GPa and hardness of 4.75 Gpa at 50 nm after 80 °C annealing, while PMMA films achieved 15.05 GPa modulus at 50 nm after 40 °C. Electrical measurements showed a significant reduction in sheet resistance from 7261 Ω/sq for as-deposited 10 nm films to 144 Ω/sq for 50 nm films annealed at 80 °C, with enhanced carrier mobility and concentration. Magnetic analysis confirmed in-plane soft magnetic behavior, with minor variations in coercivity (H<sub>c</sub>) and saturation magnetization (M<sub>s</sub>) influenced by stress relaxation and morphology-induced anisotropy. Magnetic force microscopy (MFM) indicated moderate annealing promoted ordered stripe domains, while higher temperatures induced domain coarsening. Optical characterization revealed transmittance decreased with thickness, reaching 40.68 % and 47.15 % at 10 nm on PET and PMMA at annealing 40 °C, whereas absorbance increased, indicating thickness-dominated optical behavior. These findings demonstrate that controlled annealing and thickness optimization enable precise tuning of surface roughness and multifunctional properties of CoFeGd amorphous films on flexible substrates, supporting their design for advanced flexible spintronic, electronic, and optoelectronic devices.</div></div>","PeriodicalId":331,"journal":{"name":"Intermetallics","volume":"189 ","pages":"Article 109090"},"PeriodicalIF":4.8,"publicationDate":"2025-12-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145681998","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}
Pub Date : 2025-12-05DOI: 10.1016/j.intermet.2025.109114
Tong Liu , Dezhi Chen , Xuefeng Gao , Gang Qin , Ruirun Chen
To reveal the effect of Ta on non-equiatomic AlCoCrFeNi high entropy alloys (HEAs), Ni42-xCo30Cr11Fe11Al6Tax (x = 0, 1.5, 3, 4.5, 6 at.%) HEAs were prepared. The microstructure evolution, mechanical properties and strengthening mechanism of the alloys were studied. The results show that the Ta element promotes the formation of L12 phases and Laves phases in matrix. The microstructure of the alloy changes from the single face-centered body (FCC) phases (x = 0) to the FCC + L12 phases (x˂3 at.%), and ultimately to FCC + L12+Laves phases (x ≥ 3 at.%). The tensile yield strength, ultimate tensile strength and elongation of the Ni36Co30Cr11Fe11Al6Ta6 alloy are 1065 MPa, 1250 MPa and 9.6 %, respectively. The alloy demonstrated fivefold higher yield strength than the Ta-free alloy, outperforming most cast alloys. The precipitation strengthening shows the higher contribution in the alloy. It provides a demonstration for designing high-strength as-cast HEAs.
{"title":"Microstructure and strengthening mechanism of non-equiatomic AlCoCrFeNi high entropy alloy via Ta alloying","authors":"Tong Liu , Dezhi Chen , Xuefeng Gao , Gang Qin , Ruirun Chen","doi":"10.1016/j.intermet.2025.109114","DOIUrl":"10.1016/j.intermet.2025.109114","url":null,"abstract":"<div><div>To reveal the effect of Ta on non-equiatomic AlCoCrFeNi high entropy alloys (HEAs), Ni<sub>42-<em>x</em></sub>Co<sub>30</sub>Cr<sub>11</sub>Fe<sub>11</sub>Al<sub>6</sub>Ta<sub><em>x</em></sub> (<em>x</em> = 0, 1.5, 3, 4.5, 6 at.%) HEAs were prepared. The microstructure evolution, mechanical properties and strengthening mechanism of the alloys were studied. The results show that the Ta element promotes the formation of L1<sub>2</sub> phases and Laves phases in matrix. The microstructure of the alloy changes from the single face-centered body (FCC) phases (<em>x</em> = 0) to the FCC + L1<sub>2</sub> phases (<em>x</em>˂3 at.%), and ultimately to FCC + L1<sub>2</sub>+Laves phases (<em>x</em> ≥ 3 at.%). The tensile yield strength, ultimate tensile strength and elongation of the Ni<sub>36</sub>Co<sub>30</sub>Cr<sub>11</sub>Fe<sub>11</sub>Al<sub>6</sub>Ta<sub>6</sub> alloy are 1065 MPa, 1250 MPa and 9.6 %, respectively. The alloy demonstrated fivefold higher yield strength than the Ta-free alloy, outperforming most cast alloys. The precipitation strengthening shows the higher contribution in the alloy. It provides a demonstration for designing high-strength as-cast HEAs.</div></div>","PeriodicalId":331,"journal":{"name":"Intermetallics","volume":"189 ","pages":"Article 109114"},"PeriodicalIF":4.8,"publicationDate":"2025-12-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145682040","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}
Pub Date : 2025-12-05DOI: 10.1016/j.intermet.2025.109116
Xiaofei Wu , Yusong Du , Gang Fu , Jiang Wang , Gang Cheng , Jingtai Zhao , Deqin Xu , Guanghui Rao
The intergranular Nd6Fe13M phase can effectively enhance the coercivity and thermal stability of NdFeB magnets. Investigating the magnetic properties and solidification path of Nd6Fe13M is crucial for understanding its mechanism in improving the coercivity of NdFeB magnets, as well as providing essential guidance for optimizing the preparation process of NdFeB-based alloys. In this work, a series of Nd6Fe13M (M = Cu, Ga, Ge) samples were prepared via arc melting, and their solidification path and magnetism were studied in detail. It is confirmed that the ternary Nd6Fe13M phase forms via the peritectic reaction Liquid + Fe17Nd2 ↔ Nd6Fe13M. The formation temperatures of Nd6Fe13Cu, Nd6Fe13Ga, and Nd6Fe13Ge were determined to be 875 K, 1064 K and 1206 K, respectively. Rietveld refinement confirmed that Nd6Fe13M adopts a tetragonal Nd6Fe13Si-type structure with the I4/mcm space group. Magnetic measurements revealed that all compounds exhibit antiferromagnetic ordering, with Néel temperatures of 400 K, 429 K, and 422 K, respectively. Notably, a magnetic field-induced transition from antiferromagnetic to ferromagnetic state was observed in Nd6Fe13Ge at 150 K under a maximum applied field of 5 T. Furthermore, analysis of the hysteresis loops of Nd6Fe13Cu and Nd6Fe13Ga at different temperatures suggests a competitive interplay between antiferromagnetic and ferromagnetic coupling in RE6Fe13M, with increasing temperature weakening the antiferromagnetic coupling strength.
{"title":"Study on the solidification path and magnetic properties of the ternary Nd6Fe13M (M=Cu, Ga, Ge) compounds","authors":"Xiaofei Wu , Yusong Du , Gang Fu , Jiang Wang , Gang Cheng , Jingtai Zhao , Deqin Xu , Guanghui Rao","doi":"10.1016/j.intermet.2025.109116","DOIUrl":"10.1016/j.intermet.2025.109116","url":null,"abstract":"<div><div>The intergranular Nd<sub>6</sub>Fe<sub>13</sub>M phase can effectively enhance the coercivity and thermal stability of NdFeB magnets. Investigating the magnetic properties and solidification path of Nd<sub>6</sub>Fe<sub>13</sub>M is crucial for understanding its mechanism in improving the coercivity of NdFeB magnets, as well as providing essential guidance for optimizing the preparation process of NdFeB-based alloys. In this work, a series of Nd<sub>6</sub>Fe<sub>13</sub>M (M = Cu, Ga, Ge) samples were prepared via arc melting, and their solidification path and magnetism were studied in detail. It is confirmed that the ternary Nd<sub>6</sub>Fe<sub>13</sub>M phase forms via the peritectic reaction Liquid + Fe<sub>17</sub>Nd<sub>2</sub> ↔ Nd<sub>6</sub>Fe<sub>13</sub>M. The formation temperatures of Nd<sub>6</sub>Fe<sub>13</sub>Cu, Nd<sub>6</sub>Fe<sub>13</sub>Ga, and Nd<sub>6</sub>Fe<sub>13</sub>Ge were determined to be 875 K, 1064 K and 1206 K, respectively. Rietveld refinement confirmed that Nd<sub>6</sub>Fe<sub>13</sub>M adopts a tetragonal Nd<sub>6</sub>Fe<sub>13</sub>Si-type structure with the <em>I</em>4/<em>mcm</em> space group. Magnetic measurements revealed that all compounds exhibit antiferromagnetic ordering, with Néel temperatures of 400 K, 429 K, and 422 K, respectively. Notably, a magnetic field-induced transition from antiferromagnetic to ferromagnetic state was observed in Nd<sub>6</sub>Fe<sub>13</sub>Ge at 150 K under a maximum applied field of 5 T. Furthermore, analysis of the hysteresis loops of Nd<sub>6</sub>F<sub>e13</sub>Cu and Nd<sub>6</sub>Fe<sub>13</sub>Ga at different temperatures suggests a competitive interplay between antiferromagnetic and ferromagnetic coupling in RE<sub>6</sub>Fe<sub>13</sub>M, with increasing temperature weakening the antiferromagnetic coupling strength.</div></div>","PeriodicalId":331,"journal":{"name":"Intermetallics","volume":"189 ","pages":"Article 109116"},"PeriodicalIF":4.8,"publicationDate":"2025-12-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145682105","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}
Pub Date : 2025-12-05DOI: 10.1016/j.intermet.2025.109117
Edara Abhay Choudhury , Nityananda Sahoo , Arka Ghosh , Parth Patel , Pankaj Shivastava , Syed Nasimul Alam , Rajan Kumar , Debasish Sahu , Nikhil Bogoju , Abhishek Kumar , Velaphi Msomi , Deepankar Panda
A solid phase consisting of two or more metallic or semimetallic elements with well-defined stoichiometry and an ordered structure is called an intermetallic compound (IMC). IMCs are a diverse resource to understand the relationships between atomic structure, physical characteristics, and chemical composition. In this work, elemental powders of Cu and Ti in an equiatomic ratio were mechanically alloyed (MA) to develop the CuTi IMC. After 30 h of milling, the powder was annealed for 2 h at 1000oC in an Ar atmosphere. In this novel method, Cu and Ti powders are milled in a 1:1 atomic ratio (Cu - 42.96 wt% Ti) for 30 h. The milled powder was then heated to 1000 °C for 2 h in an Ar atmosphere. Analytical methods such as high-resolution transmission electron microscopy (HRTEM), x-ray diffraction (XRD), electron dispersion x-ray spectroscopy (EDXS), scanning electron microscopy (SEM), differential scanning calorimetry, and thermogravimetric analysis (DSC/TGA) were used to verify the synthesis of CuTi. This method effectively produced nanocrystalline CuTi. This study shows that the CuTi IMC may be synthesized from the binary Cu50Ti50 by MA.
{"title":"Synthesis of CuTi intermetallic compound by mechanical alloying route","authors":"Edara Abhay Choudhury , Nityananda Sahoo , Arka Ghosh , Parth Patel , Pankaj Shivastava , Syed Nasimul Alam , Rajan Kumar , Debasish Sahu , Nikhil Bogoju , Abhishek Kumar , Velaphi Msomi , Deepankar Panda","doi":"10.1016/j.intermet.2025.109117","DOIUrl":"10.1016/j.intermet.2025.109117","url":null,"abstract":"<div><div>A solid phase consisting of two or more metallic or semimetallic elements with well-defined stoichiometry and an ordered structure is called an intermetallic compound (IMC). IMCs are a diverse resource to understand the relationships between atomic structure, physical characteristics, and chemical composition. In this work, elemental powders of Cu and Ti in an equiatomic ratio were mechanically alloyed (MA) to develop the CuTi IMC. After 30 h of milling, the powder was annealed for 2 h at 1000<sup>o</sup>C in an Ar atmosphere. In this novel method, Cu and Ti powders are milled in a 1:1 atomic ratio (Cu - 42.96 wt% Ti) for 30 h. The milled powder was then heated to 1000 °C for 2 h in an Ar atmosphere. Analytical methods such as high-resolution transmission electron microscopy (HRTEM), x-ray diffraction (XRD), electron dispersion x-ray spectroscopy (EDXS), scanning electron microscopy (SEM), differential scanning calorimetry, and thermogravimetric analysis (DSC/TGA) were used to verify the synthesis of CuTi. This method effectively produced nanocrystalline CuTi. This study shows that the CuTi IMC may be synthesized from the binary Cu<sub>50</sub>Ti<sub>50</sub> by MA.</div></div>","PeriodicalId":331,"journal":{"name":"Intermetallics","volume":"189 ","pages":"Article 109117"},"PeriodicalIF":4.8,"publicationDate":"2025-12-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145681997","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}
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