Intermetallics最新文献

{"title":"Unveiling the impact of hydrogen permeation on the nanoindentation creep behavior of plasma-sprayed Fe-based amorphous coatings","authors":"Kaicheng Zhang ,&nbsp;Xing Liu ,&nbsp;Yue He ,&nbsp;Xiyu Xiao ,&nbsp;Shijie Pan ,&nbsp;Chenrui Qian ,&nbsp;Guobing Ying","doi":"10.1016/j.intermet.2025.109057","DOIUrl":"10.1016/j.intermet.2025.109057","url":null,"abstract":"<div><div>This study examined the mechanical behavior of Fe-based amorphous coatings prepared by plasma spraying, focusing on the effects of hydrogen atom permeation in hydrogen-rich environments. Nanoindentation tests after 1, 2, and 4 h of electrochemical hydrogen permeation showed a significant decrease in hardness and creep strain rate sensitivity, indicating embrittlement similar to that in conventional metals. The embrittlement was attributed to hydrogen atoms disrupting the metal lattice, weakening atomic bonds and leading to “hydrogen embrittlement.” This work highlights the critical impact of hydrogen permeation on the performance of amorphous coatings in hydrogen-exposed conditions.</div></div>","PeriodicalId":331,"journal":{"name":"Intermetallics","volume":"188 ","pages":"Article 109057"},"PeriodicalIF":4.8,"publicationDate":"2025-11-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145526219","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":"Enhanced corrosion resistance of medium entropy metallic glass Ni-Nb-Ta-Zr and the effect of Zr addition for nuclear reprocessing application","authors":"Avinash Kumar ,&nbsp;Ch Jagadeeswara Rao ,&nbsp;Ningshen S.","doi":"10.1016/j.intermet.2025.109073","DOIUrl":"10.1016/j.intermet.2025.109073","url":null,"abstract":"<div><div>Improved corrosion resistance of structural materials for aqueous nuclear reprocessing of high burn-up fuel from emerging fast reactors is still challenging. The nickel-based medium entropy metallic glass ribbons with composition Ni₄₀Nb₃₅Zr₂₀Ta₅ and the influence of Zr addition were investigated for corrosion performance in 11.5M nitric acid of a fast reactor nuclear fuel reprocessing environment. The ingots of the Ni₆₀Nb₃₅Ta₅ and Ni₄₀Nb₃₅Zr₂₀Ta₅alloys were cast as metallic glass ribbons and characterized using X-ray diffraction (XRD), differential scanning calorimetry (DSC), Laser Raman Spectroscopy (LRS), X-ray photoelectron spectroscopy (XPS), and Scanning electron microscopy (SEM) methods. Substitution of Ni by Zr increased the range of the supercooled liquid region ΔT_x, from 25 to 44 °C. After the corrosion test of Ni₄₀Nb₃₅Zr₂₀Ta₅, the weight loss measurement showed an insignificant weight loss of ≈0.0088 mm/y. The passive current density decreased by one order in Ni₄₀Nb₃₅Zr₂₀Ta₅ compared to Ni₆₀Nb₃₅Ta₅. XPS analysis revealed the presence of oxides Nb₂O₅, Ta₂O_5, and ZrO₂. Raman peaks showed bands corresponding to Nb₂O₅ and Ta₂O₅ in Ni₆₀Nb₃₅Ta₅ and an increased peak broadening in Ni₄₀Nb₃₅Zr₂₀Ta₅ due to incorporating ZrO₂, influencing the corrosion resistance. Surface characterization indicated that the Zr substitution caused dense passive film formation with a wider passive region. However, in the case of Ni₆₀Nb₃₅Ta_5, small crystallites on the surface acted as defect sites, weakening the stability of the passive film. This work elucidated the mechanism of Zr addition and its effects on the corrosion resistance and passive film stability of Ni-Nb-Ta-Zr medium entropy metallic glass alloys (MEMGA). Medium Entropy Metallic Glass Alloy (MEMGA) is an amorphous alloy system with medium configurational entropy (ΔS range 1-1.5R), typically containing 3–4 principal elements. These innovative alloys were successfully cast, and applications with improved corrosion resistance are demonstrated, providing useful insights for designing corrosion-resistant materials.</div></div>","PeriodicalId":331,"journal":{"name":"Intermetallics","volume":"188 ","pages":"Article 109073"},"PeriodicalIF":4.8,"publicationDate":"2025-11-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145526213","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":"Thermal, mechanical and microstructural characterization of cryogenic heat treated Cu46Zr46Al8 bulk metallic glass","authors":"M.M. Rezaei ,&nbsp;R. Gholamipour ,&nbsp;F. Shahri ,&nbsp;S. Sohrabi ,&nbsp;W.H. Wang","doi":"10.1016/j.intermet.2025.109082","DOIUrl":"10.1016/j.intermet.2025.109082","url":null,"abstract":"<div><div>In this study, the effects of cryogenic thermal cycling (CTC) between ambient temperature and 77 K on the microstructure, thermal behavior, and mechanical properties of Zr₄₆Cu₄₆Al₈ bulk metallic glass (BMG) were systematically investigated. Cryogenically cycled specimens exhibited enhanced plasticity alongside reductions in yield strength, Vickers hardness, and Young's modulus, as evidenced by nanoindentation results. Concurrently, the relaxation enthalpy (<em>ΔH</em>_<em>rel</em>), quantified via the exothermic peak preceding <em>T</em>_g in differential scanning calorimetry (DSC), increased, indicating structural rejuvenation. <em>ΔH</em>_<em>rel</em> values rose with the number of cycles, peaking at 10.56 J g⁻¹ for the 15-cycle (CT15) sample, which also corresponded to the most significant decrease in mechanical strength. Microstructural evidence from SEM fracture-surface analysis revealed more abundant and closely spaced shear bands in CT15 compared to other samples subjected to more cycles, corroborating the proposed mechanism of CTC-induced rejuvenation and enhanced plasticity. HRTEM observations shows some nanostructural modifications of CT15 sample to confirm the other results.</div></div>","PeriodicalId":331,"journal":{"name":"Intermetallics","volume":"188 ","pages":"Article 109082"},"PeriodicalIF":4.8,"publicationDate":"2025-11-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145526217","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 sintering temperature on the high-temperature oxidation behavior of TiB2@Ti/AlCoCrFeNi2.1 eutectic high-entropy alloy matrix composites","authors":"Xuyang Wang ,&nbsp;Yajun Zhou ,&nbsp;Bo Ren ,&nbsp;Jianxiu Liu ,&nbsp;Aiyun Jiang","doi":"10.1016/j.intermet.2025.109078","DOIUrl":"10.1016/j.intermet.2025.109078","url":null,"abstract":"<div><div>The high-temperature oxidation behavior of TiB₂@Ti/AlCoCrFeNi_2.1 eutectic high-entropy alloy matrix composites (EHEAMCs) sintered at 950°C, 1000°C, and 1050°C was systematically investigated under isothermal oxidation at 900°C in air. The oxidation kinetics of all EHEAMCs followed a two-stage parabolic law: an initial rapid oxidation phase (1–10 h) followed by a slower steady-state phase (10–100 h). After 100 h of oxidation, the EHEAMCs sintered at 950°C exhibited the highest mass gain of 0.85 mg/cm², while the 1050°C-sintered sample demonstrated the lowest weight gain of 0.37 mg/cm². The parabolic rate constant (<em>Kp</em>) decreased significantly with increasing sintering temperature, reaching a minimum value of 7.88 × 10⁻⁸mg²⋅cm⁻⁴⋅s⁻¹ for the 1050°C EHEAMCs, indicating enhanced oxidation resistance. Cross-sectional analysis revealed distinct oxide layer configurations: 950°C and 1000°C EHEAMCs formed stratified structures with an outer TiO₂-rich layer and an inner Al₂O₃-dominated layer, whereas the 1050°C EHEAMCs exhibited discontinuous surface Al₂O₃ with internal oxide precipitates. Oxidation mechanisms transitioned from cation-dominated outward diffusion to oxygen anion inward penetration, modulated by sintering-induced densification and interfacial bonding.</div></div>","PeriodicalId":331,"journal":{"name":"Intermetallics","volume":"188 ","pages":"Article 109078"},"PeriodicalIF":4.8,"publicationDate":"2025-11-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145526212","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 ion nitriding on microstructures and properties of laser cladding AlxCoCrFeNiTi0.25 high entropy alloys coatings","authors":"Meiyan Li ,&nbsp;Jiayang Song ,&nbsp;Pu Li ,&nbsp;Lixin Song ,&nbsp;Dan Li ,&nbsp;Chunyang Hu ,&nbsp;Bin Han","doi":"10.1016/j.intermet.2025.109070","DOIUrl":"10.1016/j.intermet.2025.109070","url":null,"abstract":"<div><div>Al_xCoCrFeNiTi_0.25 (x = 0, 0.5, 0.6, 0.8, 1.0) coatings were fabricated via laser cladding and subsequently subjected to ion nitriding treatment to enhance their mechanical properties. Effect of ion nitriding on microstructures, phase composition, hardness and wear resistance of Al_xCoCrFeNiTi_0.25 cladding coatings were investigated by means of scanning electron microscopy(SEM), X-ray diffraction (XRD), Vickers microhardness testing and material surface performance comprehensive tester. The results revealed that the thickness of the nitriding layer initially increased and then decreased with increasing Al content. XRD analysis revealed that CoCrFeNiTi_0.25 nitrided layer was composed of Fe₄N and CrN while AlN appeared in the Al-containing Al_xCoCrFeNiTi_0.25 HEA coatings. The microhardness of the as-clad Al_xCoCrFeNiTi_0.25 coating gradually increased from 210HV_0.2 to 610HV_0.2 with an increase in Al content. After ion nitriding the microhardness of Al_xCoCrFeNiTi_0.25 nitrided layer further enhanced significantly, reaching 963.2HV_0.2, 1035.3HV_0.2,1065.5HV_0.2, 1206HV_0.2, 1276.3HV_0.2, respectively when x value varied from 0 to 1.0. Moreover, compared with untreated laser cladding coatings, the wear resistance of the nitrided layers was improved while the Al_1.0CoCrFeNiTi_0.25 nitrided coating exhibited the lowest wear rate of 0.351 × 10⁻⁵cm³/(N/m), significantly lower than that of the corresponding cladding coating (2.66 × 10⁻⁵cm³/(N/m)). After nitriding treatment, the worn mechnism transformed into fatigue spallling and oxidative wear. In summary, ion nitriding effectively modified the microstructure and phase composition of Al_xCoCrFeNiTi_0.25 coatings, resulting in substantial improvements in hardness and wear resistance.</div></div>","PeriodicalId":331,"journal":{"name":"Intermetallics","volume":"188 ","pages":"Article 109070"},"PeriodicalIF":4.8,"publicationDate":"2025-11-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145526218","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":"Phase evolution and nanomechanical characteristics of cold-sprayed Cu-based amorphous coatings","authors":"Yujun Wang ,&nbsp;Yuping Wu ,&nbsp;Zheng Wei ,&nbsp;Junpeng Lv ,&nbsp;Sheng Hong ,&nbsp;Jiangbo Cheng ,&nbsp;Shuaishuai Zhu","doi":"10.1016/j.intermet.2025.109063","DOIUrl":"10.1016/j.intermet.2025.109063","url":null,"abstract":"<div><div>A Cu-based amorphous coating (C1) was fabricated via cold spraying and then annealed to yield samples with crystallinities of approximately 30 % (C2) and 60 % (C3). The phase evolution and corresponding nanomechanical characteristics were investigated, and a new method for identifying pop-in events was developed. C1 was found to have an amorphous structure with minor amounts of nano-ZrO₂ and nano-TiO₂. The crystallization products consisted of a primary phase Cu₅₁Ti₁₄ and a secondary phase CuTi. The hardness and elastic modulus of C1 were 6.50 ± 1.12 GPa and 99.55 ± 10.30 GPa, respectively. After annealing, the hardness exhibited a parabolic variation, whereas the elastic modulus increased linearly. The creep of C1 and C2 was governed by the activation of interstitial defects and free volume, whereas creep in C3 was mainly influenced by crystalline defects. The first-order differences of the loading curves for all three coatings followed a negative power-law distribution. Using the upper bound of the fitted 95 % prediction interval as a threshold provided a reliable criterion for identifying pop-in events. Pop-in events were prominent in both C1 and C3, whereas they were significantly suppressed in C2. This study advances the development of Cu-based amorphous alloys and proposes a feasible approach for the rapid and effective identification of pop-in events.</div></div>","PeriodicalId":331,"journal":{"name":"Intermetallics","volume":"188 ","pages":"Article 109063"},"PeriodicalIF":4.8,"publicationDate":"2025-11-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145526216","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 corrosion behavior and mechanism of hot isostatically pressed CrMnFeCoNi high-entropy alloy in high-temperature molten salt environments","authors":"Jiatao Lv ,&nbsp;Jiahao Liu ,&nbsp;Shuwen Guo ,&nbsp;Jing Zhang ,&nbsp;Chunyu Chen ,&nbsp;Chuanbo Zheng ,&nbsp;Zhanfang Wu ,&nbsp;Xiangyang Li ,&nbsp;Dianchun Ju","doi":"10.1016/j.intermet.2025.109074","DOIUrl":"10.1016/j.intermet.2025.109074","url":null,"abstract":"<div><div>CrMnFeCoNi high-entropy alloy (HEA) was fabricated via hot isostatic pressing (HIP), and its high-temperature corrosion behavior and mechanism in NaCl-KCl molten salts were systematically investigated. The alloy exhibited a single FCC phase with a homogeneous elemental distribution and no noticeable segregation. The corrosion products were mainly identified as Cr₂O₃, Mn₂O₃, Fe₂O₃, Mn₃O₄, and MnCr₂O₄ spinel oxides. At 650 °C and 750 °C, the alloy showed relatively stable surface morphologies, with both weight loss and corrosion rate increasing linearly with time. In contrast, at 850 °C, the surface morphology became more complex, dominated by porous spinel oxides, accompanied by a pronounced acceleration in weight loss and corrosion rate. By performing an Arrhenius fit of the linear rate constant k_l at multiple temperatures, the activation energy of the linear corrosion process was determined to be 120.4 kJ/mol. Thermodynamic calculations of Gibbs free energy (ΔG) revealed that Mn and Cr possess high reactivity toward O₂ and Cl₂, leading to the preferential formation of Cr₂O₃-, Mn₂O₃-, and minor Fe₂O₃-rich oxide layers during the early corrosion stage. With prolonged exposure, progressive spallation of the oxide scale facilitated the ingress of molten salts, promoting severe substrate attack, the development of new Cr₂O₃- and Mn₂O₃-rich layers, internal oxidation, and the formation of increasingly coarse spinel oxides at the alloy surface.</div></div>","PeriodicalId":331,"journal":{"name":"Intermetallics","volume":"188 ","pages":"Article 109074"},"PeriodicalIF":4.8,"publicationDate":"2025-11-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145526220","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":"A Cu-rich medium-entropy alloy with high strength and outstanding corrosion resistance","authors":"Liran Huang ,&nbsp;Shiyu Liu ,&nbsp;Chenliang Chu ,&nbsp;Yubin Ke ,&nbsp;Hao Wang ,&nbsp;Zhiqiang Fu","doi":"10.1016/j.intermet.2025.109064","DOIUrl":"10.1016/j.intermet.2025.109064","url":null,"abstract":"<div><div>The widely used marine materials, nickel aluminum bronzes (NAB), are facing a bottleneck of improving their limited strength and moderate corrosion resistance. In this study, we proposed a novel face-centered cubic (FCC) Cu₄₈Ni₁₇Cr₁₀Al₁₀Co₇Fe₅Mn₃ (at.%) medium-entropy alloy (MEA) strengthened by coherent L1₂ nanoprecipitates and two types of other secondary phases. One secondary phase exhibited FCC/L1₂ structure with spinodal decomposition, while the other BCC/B2 phase displayed a core-shell structure. Compared with the typical as-cast NAB, the mechanical properties and corrosion resistance of the as-cast Cu-rich MEA were simultaneously improved. Specifically, its tensile yield strength was increased from ∼343 MPa to ∼564 MPa, total elongation was increased from ∼22.4 % to ∼26.5 %, and corrosion current density was reduced by three orders of magnitude. Our results confirmed that the Cu-rich MEA displays a heretofore unattainable combination of mechanical performance and corrosion resistance when compared to those of previously studied Cu-bearing alloys. This impressive combination of strength and ductility was primarily attributed to the synergistic effect of multiple secondary phases, and outstanding corrosion resistance originated from the stabilized and dense passive film. The results presented here validate the hypothesis that the concept of Cu-rich MEA provides a powerful strategy to enhance the corrosion resistance and mechanical response of conventional Cu-bearing alloys.</div></div>","PeriodicalId":331,"journal":{"name":"Intermetallics","volume":"188 ","pages":"Article 109064"},"PeriodicalIF":4.8,"publicationDate":"2025-11-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145474512","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":"Phase-field study on effects of elastic energy and aging temperature on precipitation kinetics of γ′ phase in nickel-based superalloys","authors":"Haipeng Zhou ,&nbsp;Daming Tong ,&nbsp;Rui Wang ,&nbsp;Yecong Shen ,&nbsp;Lizhan Han ,&nbsp;Jianfeng Gu","doi":"10.1016/j.intermet.2025.109069","DOIUrl":"10.1016/j.intermet.2025.109069","url":null,"abstract":"<div><div>A phase-field model (PFM) for the precipitation of γ′ phases in nickel-based single crystal superalloys (Ni-SXs) during aging process is established, with DD10 alloy used as the research object, and the precipitation and evolution of γ′ phase during aging are simulated. The reliability of the model is confirmed through quantitative comparison with experimental results. The average errors between the simulated and experimental results for the γʹ precipitates volume fraction, size, and number after aging at 1143 K, 1273 K, and 1393 K are 20.86 %, 8.58 %, and 10.5 %, respectively. Based on the proposed model, the microstructure evolution under different aging conditions is simulated to analyze the effects of elastic energy and temperature on the precipitation kinetics, concentration fields, and stress-strain distributions within γ′ phase microstructure. The results indicate that the growth process of the γʹ precipitates during aging can be divided into a rapid growth stage and a ripening growth stage. The relationship between the number, size, and time of the γʹ precipitates can all be fitted using a power function. The average stress firstly increases and then decreases during aging process. The Al concentrations within both the γʹ phase and the γ matrix are relatively uniform, with the concentration in the γʹ phase significantly higher than that in the γ matrix. The Al concentration, stress and strain at the interface are slightly higher. Elastic energy exerts an inhibitory effect on Ostwald ripening, while temperature promotes the growth of the γʹ precipitates. Elastic energy slows down the variation of the number and average size of γʹ precipitates, whereas higher temperatures accelerate these processes.</div></div>","PeriodicalId":331,"journal":{"name":"Intermetallics","volume":"188 ","pages":"Article 109069"},"PeriodicalIF":4.8,"publicationDate":"2025-11-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145474511","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":"A new Nd2Fe15Ga2 phase - Driven grain boundary engineering: A breakthrough for high-coercivity Ga-doped Nd-Fe-B magnets","authors":"Leshen Chang ,&nbsp;Xiaojun Sun ,&nbsp;Dunbo Yu ,&nbsp;Xuexu Gao ,&nbsp;Xiaoqian Bao ,&nbsp;Weiguo Gao ,&nbsp;Xiao Lin ,&nbsp;Zilong Wang ,&nbsp;Wenlong Yan ,&nbsp;Yang Luo","doi":"10.1016/j.intermet.2025.109058","DOIUrl":"10.1016/j.intermet.2025.109058","url":null,"abstract":"<div><div>An important idea for the fabrication of high coercivity Nd-Fe-Ga-B magnets is the careful tuning of the Nd₆Fe₁₃Ga intergranular phase. However, the influence of other Nd-Fe-Ga ternary compounds in the grain boundaries on the microstructure and magnetic properties of magnets remains underexplored, and the related mechanisms are still unclear. In this study, the Nd₂Fe₁₅Ga₂ phase was found as the precursor phase of the Nd₆Fe₁₃Ga phase in Nd-Fe-Ga-B magnets by adjusting the annealing process. The results show that the coercivity of magnets containing Nd₂Fe₁₅Ga₂ phase is about 0.5 kOe higher than those containing Nd₆Fe₁₃Ga phase. Moreover, the mechanism of coercivity enhancement and phase transition between the Nd₂Fe₁₅Ga₂ phase and the Nd₆Fe₁₃Ga phase was investigated. Comparing the magnets containing two different grain boundary phases, the generation of the Nd₂Fe₁₅Ga₂ phase allows more Fe elements to be enriched in the triangular grain boundary region and consumes less rare earth elements. The grain boundary phase of the magnet, containing the Nd₂Fe₁₅Ga₂ phase, exhibits a reduced saturation magnetization. This diminished saturation magnetization has a more pronounced effect on the reduction of exchange coupling between the main phase grains. As a result, it leads to a significant enhancement in the coercivity of the magnet associated with the Nd₂Fe₁₅Ga₂ phase. This study provides a novel approach to regulating magnet grain boundary phases, along with new insights and theoretical guidance for the development of heavy rare-earth-free magnets.</div></div>","PeriodicalId":331,"journal":{"name":"Intermetallics","volume":"188 ","pages":"Article 109058"},"PeriodicalIF":4.8,"publicationDate":"2025-11-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145474258","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}