金属热处理 ›› 2021, Vol. 46 ›› Issue (6): 160-167.DOI: 10.13251/j.issn.0254-6051.2021.06.032

• 组织与性能 • 上一篇    下一篇

不完全再结晶Fe40Mn10Cr25Ni25高熵合金的室温及低温力学性能

武雅桃1, 黄德军2, 杨慧君1,3, 张敏1, 乔珺威1,3   

  1. 1.太原理工大学 材料科学与工程学院, 山西 太原 030024;
    2.(中国)上海思百吉仪器系统有限公司, 上海 201100;
    3.太原理工大学 新材料界面科学与工程教育部重点实验室, 山西 太原 030024
  • 收稿日期:2021-04-16 出版日期:2021-06-25 发布日期:2021-07-21
  • 通讯作者: 乔珺威,教授,博士生导师,E-mail:qiaojunwei@gmail.com
  • 作者简介:武雅桃(1994—),女,硕士研究生,主要研究方向为高熵合金的变形行为,E-mail:wuyatao3@hotmail.com。
  • 基金资助:
    山西省自然科学基金(201901D111105,201901D111114);新金属材料国家重点实验室开放课题(2020-Z09)

Room temperature and cryogenic temperature mechanical properties of partially recrystallized Fe40Mn10Cr25Ni25 high-entropy alloy

Wu Yatao1, Huang Dejun2, Yang Huijun1,3, Zhang Min 1, Qiao Junwei1,3   

  1. 1. College of Materials Science and Engineering, Taiyuan University of Technology, Taiyuan Shanxi 030024, China;
    2. Malvern Panalytical (China) Co., Ltd., Shanghai 201100, China;
    3. Key Laboratory of Interface Science and Engineering in Advanced Materials, Ministry of Education, Taiyuan University of Technology, Taiyuan Shanxi 030024, China
  • Received:2021-04-16 Online:2021-06-25 Published:2021-07-21

摘要: 采用冷轧和退火热处理工艺制备了不完全再结晶结构的Fe40Mn10Cr25Ni25高熵合金,分析了合金的室温(298 K)及低温(77 K)拉伸时的力学性能。结果表明,合金具有优良的室温及低温力学性能,合金在低温拉伸时强度和塑性均得到了提高,其室温强度和断后伸长率分别为880 MPa和18%,低温强度和断后伸长率分别为1360 MPa和36%。合金在室温变形以位错滑移为主,低温变形以位错滑移和孪生为主。室温拉伸时,粗晶晶粒先于细晶晶粒变形,导致试样内部产生了应变梯度,提高了合金的加工硬化率,使合金在室温下具有良好的强塑性。低温拉伸时,粗晶晶粒中形成了大量的变形孪晶,从而提高了合金的低温力学性能。

关键词: 高熵合金, 显微组织, 力学性能, 位错, 孪晶

Abstract: The Fe40Mn10Cr25Ni25 high-entropy alloy (HEA) with partial recrystallization was prepared by cold rolling and subsequent annealing. The tensile properties of the alloy at room temperature (298 K) and cryogenic temperature (77 K) were studied. The results show that the alloy has excellent room temperature and cryogenic temperature mechanical properties. Both the strength and ductility of the alloy are improved under tension at cryogenic temperature. The strength and percentage elongation after fracture at room temperature are 880 MPa and 18% respectively, and 1360 MPa and 36% respectively at 77 K. The tensile deformation of the alloy at room temperature is dominated by dislocation slip, but by dislocation slip and twinning at cryogenic temperature. The coarse grains deform before fine grains under tensile stress at room temperature, resulting in a strain gradient inside the specimen, so that the work hardening rate of the alloy is increased, the alloy exhibits excellent combination of strength and ductility at room temperature. A large quantity of high-density deformation twins are formed in the coarse grains under tensile stress at cryogenic temperature, so that the cryogenic temperature mechanical properties of the alloy can be improved.

Key words: high-entropy alloy, microstructure, mechanical properties, dislocation, twin

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