金属热处理 ›› 2020, Vol. 45 ›› Issue (8): 161-165.DOI: 10.13251/j.issn.0254-6051.2020.08.031

• 工艺研究 • 上一篇    下一篇

热处理对挤压态Mg-6Gd-5Y-1Zn合金组织与性能的影响

许恒源1, 甄睿1,2, 毛忠峰3, 吴震1, 戴圣朋1   

  1. 1.南京工程学院 材料科学与工程学院, 江苏 南京 211167;
    2.江苏省先进结构材料与应用技术重点实验室, 江苏 南京 211167;
    3.南京莱斯信息技术股份有限公司, 江苏 南京 210014
  • 收稿日期:2020-02-04 出版日期:2020-08-25 发布日期:2020-09-07
  • 通讯作者: 甄 睿,副教授,博士,E-mail: zhenr@njit.edu.cn
  • 作者简介:许恒源(1999—),男,主要研究方向为金属材料的组织和性能,E-mail:2314856869@qq.com
  • 基金资助:
    江苏省大学生创新创业训练计划(201911276034Y);南京工程学院大学生科技创新基金(TB202002028);江苏高校优秀科技创新团队

Effect of heat treatment on microstructure and properties of as-extruded Mg-6Gd-5Y-1Zn alloy

Xu Hengyuan1, Zhen Rui1,2, Mao Zhongfeng3, Wu Zhen1, Dai Shengpeng1   

  1. 1. School of Materials Science and Engineering, Nanjing Institute of Technology, Nanjing Jiangsu 211167, China;
    2. Jiangsu Key Laboratory of Advanced Structural Materials and Application Technology, Nanjing Jiangsu 211167, China;
    3. Nanjing Les Information Technology Co. , Ltd. , Nanjing Jiangsu 210014, China
  • Received:2020-02-04 Online:2020-08-25 Published:2020-09-07

摘要: 通过对Mg-6Gd-5Y-1Zn(质量分数,%)合金在固溶和时效处理状态下显微组织和力学性能的研究发现,α-Mg基体、沿挤压方向分布的条状18R-LPSO相、少量的Mg24(GdYZn)5 相以及细层片状的14H-LPSO相构成了挤压态合金的组成相。挤压态合金经固溶(T4)处理后,一部分18R-LPSO相溶入基体,并且基体中的14H-LPSO相伸长同时粗化。挤压态合金经过固溶加时效(T6)处理后,大量β′相从α-Mg基体中析出。T6态合金的室温力学性能最好,其屈服强度、抗拉强度及伸长率分别为272 MPa、406 MPa和6.1%。β′相沉淀也发生在挤压态合金的直接人工时效(T5)处理过程,但相比于T6处理,14H-LPSO相和β′相在基体中的体积分数均偏低。

关键词: 镁合金, 长周期结构, 沉淀相, 热挤压, 固溶, 时效

Abstract: Microstructure and mechanical properties of as-extruded Mg-6Gd-5Y-1Zn (mass fraction, %) alloy after solid solution and aging treatment were investigated. The results show that the as-extruded alloy is composed of α-Mg matrix, strip shaped 18R-LPSO phase arranged parallel to extrusion direction, Mg24(GdYZn)5phase and fine lamellar 14H-LPSO phase. Solid solution (T4) treatment of the as-extruded alloy at high temperature results in the dissolution of 18R-LPSO phase into the matrix and the lengthening and coarsening of the 14H-LPSO phase. A large number of β′ precipitates exist in the microstructure of the T6 treated specimens. The T6 treated specimen shows the best tensile properties at room temperature with tensile strength of 406 MPa, yield strength of 272 MPa and elongation of 6.1%. T5 treatment also results in the β′ precipitation but its volume fraction, as well as the volume fraction of the 14H-LPSO phase are much lower than that of the T6 treated specimens.

Key words: magnesium alloy, long period stacking ordered structure (LPSO), precipitated phase, hot extrusion, solid solution, aging

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