兰州理工大学学报 ›› 2025, Vol. 51 ›› Issue (3): 1-8.

• 材料科学与工程 •    下一篇

等温热处理对Mg-xZn-0.3La-0.3Si镁合金组织的影响

黄晓锋*1,2, 贺光亮1, 陈宣宇1, 张鑫涛1, 陶伟1, 何丹丹1   

  1. 1.兰州理工大学 省部共建有色金属先进加工与再利用国家重点实验室, 甘肃 兰州 730050;
    2.兰州理工大学 有色金属合金及加工教育部重点实验室, 甘肃 兰州 730050
  • 收稿日期:2024-04-02 出版日期:2025-06-28 发布日期:2025-06-30
  • 通讯作者: 黄晓锋(1971-),男,吉林白城人,博士,副教授.Email:huangxf_lut@163.com
  • 基金资助:
    甘肃省科技重大专项资助项目(22ZD6GA008)

Evolution of non-dendrite microstructure of Mg-xZn-0.3La-0.3Si magnesium alloy

HUANG Xiao-feng1,2, HE Guang-liang1, CHEN Xuan-yu1 ZHANG Xin-tao1, TAO Wei1, HE Dan-dan1   

  1. 1. State Key Laboratory of Advanced Processing and Recycling of Non-ferrous Metals, Lanzhou University of Technology, Lanzhou 730050, China;
    2. Key Laboratory of Non-ferrous Metal Alloys and Processing, Ministry of Education, Lanzhou University of Technology, Lanzhou 730050, China
  • Received:2024-04-02 Online:2025-06-28 Published:2025-06-30

摘要: 采用等温热处理法对Mg-9Zn-0.3La-0.3Si合金进行不同时间与不同温度的热处理,研究了保温温度与保温时间对Mg-9Zn-0.3La-0.3Si合金非枝晶组织演变的影响,并分析非枝晶颗粒的形成机理.结果表明:等温热处理可以将Mg-9Zn-0.3La-0.3Si合金铸态枝晶组织转变为球状的非枝晶颗粒组织.合金在585 ℃保温30 min时获得的非枝晶组织最为理想,其固相率、形状因子和颗粒平均尺寸分别为74%、1.32及 63.59 μm.随着保温时间的延长或保温温度的增加,非枝晶颗粒平均尺寸和形状因子先减小后增大,非枝晶组织的固相率持续降低.非枝晶组织演变主要分为初始粗化、枝晶熔断和晶粒球化、颗粒合并及熟化3个阶段.

关键词: Mg-Zn-La-Si镁合金, 半固态, 等温热处理

Abstract: The Mg-9Zn-0.3La-0.3Si alloy was subjected to isothermal heat treatment at different temperatures and different durations, and the influence of holding temperature and holding time on the evolution of non-dendritic structure in Mg-9Zn-0.3La-0.3Si alloy were studied. The formation mechanism of non-dendritic grains was also analyzed. The experimental results showed that isothermal heat treatment can transform the as-cast dendritic structure of Mg-9Zn-0.3La-0.3Si alloy into spherical non-dendritic grain structure. The ideal non-dendritic structure is obtained at a holding temperature of 585 ℃ for 30 minutes, with a solid-phase fraction, shape factor, and average grain size of 74%, 1.32, and 63.59 μm, respectively. With the extension of holding time or the increase of holding temperature, the average size and shape factor of non-dendritic grains first decrease and then increase, while the solid-phase fraction of non-dendritic structure continues to decrease. The evolution of non-dendritic structure mainly includes three stages: initial coarsening, dendrite melting and grain spheroidization, grain coalescence and maturation.

Key words: Mg-Zn-La-Si magnesium alloy, semi-solid state, isothermal heat treatment

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