陆寒,何杰军,苏向东,杨江

• 1:贵州大学材料与冶金学院
• 2:贵州理工学院材料与能源工程学院

摘要(Abstract)：

对AZ91镁合金进行了直接搅拌摩擦焊接及焊前预固溶搅拌摩擦焊接实验。采用扫描电镜(SEM)、透射电镜(TEM)、电子探针(EPMA)和拉伸实验等分析了焊接接头的微观结构和力学性能。结果表明：直接搅拌摩擦焊接后接头搅拌区的微观结构由于晶粒细化和粗大第二相的破碎、溶解及再析出而得到改善，然而大量粗大的β相在焊缝后退侧过渡区连续性聚集，使得该β相与基体之间的界面成为裂纹萌生源。直接搅拌摩擦焊接头的拉伸强度及断后伸长率分为136.68 MPa和2.34%,对铸态AZ91镁合金在400℃固溶12 h后，其焊接接头的拉伸强度及断后伸长率分别为184.81 MPa和6.79%。尽管焊前预固溶搅拌摩擦焊接接头的搅拌区平均晶粒尺寸较直接焊接接头的稍大，但是微观结构较直接焊接更加均匀。说明预固溶处理能够显著改善焊缝区域第二相的分布，使镁合金变形协调性增加，显著提高了焊件的强度和塑性。

关键词(KeyWords)： AZ91镁合金;搅拌摩擦焊;β-Mg_(17)Al_(12);力学性能

Abstract:

Keywords:

基金项目(Foundation): 贵州省科学技术基金项目([2019]1141);; 贵州省高等学校教学内容和课程体系改革项目(2021200)

作者(Author): 陆寒,何杰军,苏向东,杨江

DOI: 10.13289/j.issn.1009-6264.2022-0463

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