金属热处理 ›› 2022, Vol. 47 ›› Issue (12): 216-221.DOI: 10.13251/j.issn.0254-6051.2022.12.036

• 组织与性能 • 上一篇    下一篇

轻质MgAlSnZnCu高熵合金的微观组织和力学性能

杨拓宇1, 王克鸿2, 张德库2, 陈丰1, 郭纯1, 张雅晶1   

  1. 1.安徽科技学院 机械工程学院, 安徽 蚌埠 233100;
    2.南京理工大学 材料科学与工程学院, 江苏 南京 210094
  • 收稿日期:2022-07-31 修回日期:2022-10-31 出版日期:2022-12-25 发布日期:2023-01-05
  • 作者简介:杨拓宇(1975—),男,副教授,博士,主要研究方向为新型焊接材料及方法,E-mail:yangtuoyu@126.com
  • 基金资助:
    安徽省教育厅重点项目(KJ2020A0072);安徽科技学院自然科学项目(2021zrzd02)(100005)

Microstructure and mechanical properties of MgAlSnZnCu lightweight high entropy alloys

Yang Tuoyu1, Wang Kehong2, Zhang Deku2, Chen Feng1, Guo Chun1, Zhang Yajing1   

  1. 1. School of Mechanical Engineering, Anhui Science and Technology University, Bengbu Anhui 233100, China;
    2. School of Material Science and Engineering, Nanjing University of Science and Technology, Nanjing Jiangsu 210094, China
  • Received:2022-07-31 Revised:2022-10-31 Online:2022-12-25 Published:2023-01-05

摘要: 为了提高阻隔层的稳定性,研究采用电磁感应加热方法,在覆盖剂和氩气保护作用下制备MgAlSnZnCu系列轻质高熵合金。使用扫描电镜(SEM)、X射线衍射(XRD)、能谱分析(EDS)对合金的铸造组织、退火组织和物相进行了表征和分析,同时采用显微硬度测试方法对其硬度进行了研究。结果表明,铸态MgAlSnZnCu合金组织由(AlMgZnCu)-FCC相和Mg2Sn相组成,Mg2Sn相的形态为2~6 μm粒状和不规则块状。Mg的含量由22%降低到12%,其合金的硬度由277 HV0.2增加到326 HV0.2,抗压强度由223 MPa增加到237 MPa。Sn和Zn含量降低后组织中出现了针状和片状的杂质相,且硬度值分散度较大,在450 ℃保温6 h的退火工艺条件下,组织中的杂质相出现明显的积聚长大的趋势。力学性能测试显示退火对抗压强度和硬度的影响不大,MgAlSnZnCu系列合金在450 ℃的条件下能保持较好的热稳定性。

关键词: 轻质高熵合金, 扩散退火, 组织, 维氏硬度, 抗压强度

Abstract: In order to improve the stability of the barrier layer, MgAlSnZnCu series of lightweight high entropy alloys were prepared by electromagnetic induction heating method under the protection of a covering agent and argon gas. The as-cast microstructure, annealed microstructure and phases of the alloys were characterized and analyzed by means of X-ray diffraction (XRD), scanning electron microscopy (SEM), energy spectrum analysis (EDS), and microhardness test was used to study its hardness. The results show that the microstructure of as-cast MgAlSnZnCu alloy is composed of (AlMgZnCu)-FCC phase and Mg2Sn phase. The morphology of Mg2Sn phase is 2-6 μm granular and irregular block. When the content of Mg decreases from 22% to 12%, the hardness of the alloy increases from 277 HV0.2 to 326 HV0.2, and the compressive strength increases from 223 MPa to 237 MPa. Needle-like and flake-like impurity phases appear in the microstructure after the decrease of Sn and Zn contents, and the dispersion of hardness values is large, after annealing at 450 ℃ for 6 h, the impurity phases in the microstructure tend to accumulate and grow obviously. The mechanical test results show that the annealing have little effect on compressive strength and hardness. The MgAlSnZnCu series alloys can maintain good thermal stability at 450 ℃.

Key words: lightweight high entropy alloys, diffusion annealling, microstructure, vickers hardness, compressive strength

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