{"title":"采用粉末冶金方法制备具有高密度L12纳米析出相的富镍镍铬基中熵合金","authors":"Hong Huang , Zixuan Wu , Lanping Huang , Song Li","doi":"10.1016/j.msea.2025.148923","DOIUrl":null,"url":null,"abstract":"<div><div>A Ni-rich NiCoCr-based medium-entropy alloy (MEA) was successfully fabricated via gas atomization followed by spark plasma sintering (SPS). By controlling the sintering temperature at 1200 °C, a fully recrystallized dual-phase microstructure was achieved, consisting of a face-centered cubic (FCC) matrix and a high density of uniformly dispersed L1<sub>2</sub> nano-precipitates (20–45 nm in size, occupying 58–60 vol%). This unique microstructure significantly improved the mechanical characteristics of the alloy. The (Ni<sub>3.5</sub>Co<sub>3</sub>Cr<sub>1.5</sub>)<sub>90</sub>Al<sub>5</sub>Ti<sub>5</sub> MEA demonstrated outstanding mechanical properties, achieving a yield strength of 1055 ± 10 MPa, an ultimate tensile strength of 1411 ± 5 MPa, and an elongation of 24.33 ± 0.3 %. This exceptional integration of strength and ductility was primarily attributed to the synergistic influence of high-density L1<sub>2</sub> nano-precipitates, the occurrence of annealing and deformation twins, and the refinement of ultrafine grains, averaging 6.46 μm in size. Compared with the sample sintered at 1000 °C, the sintered sample at 1200 °C demonstrated higher relative density, increasing stacking faults, and more deformation twins, which effectively alleviated stress concentration and improved plasticity. This work not only enhances our comprehension of non-equiatomic MEAs but also opens up a new pathway for developing new engineering metallic materials with tailored properties.</div></div>","PeriodicalId":385,"journal":{"name":"Materials Science and Engineering: A","volume":"944 ","pages":"Article 148923"},"PeriodicalIF":7.0000,"publicationDate":"2025-08-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"Achieving high strength and ductility in Ni-rich NiCoCr-based medium-entropy alloy with high-density L12 nano-precipitates by powder metallurgy\",\"authors\":\"Hong Huang , Zixuan Wu , Lanping Huang , Song Li\",\"doi\":\"10.1016/j.msea.2025.148923\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<div><div>A Ni-rich NiCoCr-based medium-entropy alloy (MEA) was successfully fabricated via gas atomization followed by spark plasma sintering (SPS). By controlling the sintering temperature at 1200 °C, a fully recrystallized dual-phase microstructure was achieved, consisting of a face-centered cubic (FCC) matrix and a high density of uniformly dispersed L1<sub>2</sub> nano-precipitates (20–45 nm in size, occupying 58–60 vol%). This unique microstructure significantly improved the mechanical characteristics of the alloy. The (Ni<sub>3.5</sub>Co<sub>3</sub>Cr<sub>1.5</sub>)<sub>90</sub>Al<sub>5</sub>Ti<sub>5</sub> MEA demonstrated outstanding mechanical properties, achieving a yield strength of 1055 ± 10 MPa, an ultimate tensile strength of 1411 ± 5 MPa, and an elongation of 24.33 ± 0.3 %. This exceptional integration of strength and ductility was primarily attributed to the synergistic influence of high-density L1<sub>2</sub> nano-precipitates, the occurrence of annealing and deformation twins, and the refinement of ultrafine grains, averaging 6.46 μm in size. Compared with the sample sintered at 1000 °C, the sintered sample at 1200 °C demonstrated higher relative density, increasing stacking faults, and more deformation twins, which effectively alleviated stress concentration and improved plasticity. This work not only enhances our comprehension of non-equiatomic MEAs but also opens up a new pathway for developing new engineering metallic materials with tailored properties.</div></div>\",\"PeriodicalId\":385,\"journal\":{\"name\":\"Materials Science and Engineering: A\",\"volume\":\"944 \",\"pages\":\"Article 148923\"},\"PeriodicalIF\":7.0000,\"publicationDate\":\"2025-08-06\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Materials Science and Engineering: A\",\"FirstCategoryId\":\"5\",\"ListUrlMain\":\"https://www.sciencedirect.com/science/article/pii/S0921509325011475\",\"RegionNum\":2,\"RegionCategory\":\"材料科学\",\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q1\",\"JCRName\":\"MATERIALS SCIENCE, MULTIDISCIPLINARY\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Materials Science and Engineering: A","FirstCategoryId":"5","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S0921509325011475","RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"MATERIALS SCIENCE, MULTIDISCIPLINARY","Score":null,"Total":0}
Achieving high strength and ductility in Ni-rich NiCoCr-based medium-entropy alloy with high-density L12 nano-precipitates by powder metallurgy
A Ni-rich NiCoCr-based medium-entropy alloy (MEA) was successfully fabricated via gas atomization followed by spark plasma sintering (SPS). By controlling the sintering temperature at 1200 °C, a fully recrystallized dual-phase microstructure was achieved, consisting of a face-centered cubic (FCC) matrix and a high density of uniformly dispersed L12 nano-precipitates (20–45 nm in size, occupying 58–60 vol%). This unique microstructure significantly improved the mechanical characteristics of the alloy. The (Ni3.5Co3Cr1.5)90Al5Ti5 MEA demonstrated outstanding mechanical properties, achieving a yield strength of 1055 ± 10 MPa, an ultimate tensile strength of 1411 ± 5 MPa, and an elongation of 24.33 ± 0.3 %. This exceptional integration of strength and ductility was primarily attributed to the synergistic influence of high-density L12 nano-precipitates, the occurrence of annealing and deformation twins, and the refinement of ultrafine grains, averaging 6.46 μm in size. Compared with the sample sintered at 1000 °C, the sintered sample at 1200 °C demonstrated higher relative density, increasing stacking faults, and more deformation twins, which effectively alleviated stress concentration and improved plasticity. This work not only enhances our comprehension of non-equiatomic MEAs but also opens up a new pathway for developing new engineering metallic materials with tailored properties.
期刊介绍:
Materials Science and Engineering A provides an international medium for the publication of theoretical and experimental studies related to the load-bearing capacity of materials as influenced by their basic properties, processing history, microstructure and operating environment. Appropriate submissions to Materials Science and Engineering A should include scientific and/or engineering factors which affect the microstructure - strength relationships of materials and report the changes to mechanical behavior.