夹层辅助激光焊接镁/钢异种金属的显微组织与性能  

Microstructure and properties of magnesium/steel dissimilar metals by interlayer assisted laser welding

作　　者：陶韬 刘金水[1,2] 周惦武[2] 李会明 王新宇 Tao TAO;Jin-shui LIU;Dian-wu ZHOU;Hui-ming LI;Xin-yu WANG(College of Materials Science and Engineering,Hunan University,Changsha 410082,China;State Key Laboratory of Advanced Design and Manufacturing for Vehicle Body,Hunan University,Changsha 410082,China)

机构地区：[1]湖南大学材料科学与工程学院,长沙410082 [2]湖南大学汽车车身先进设计制造国家重点实验室,长沙410082

出　　处：《Transactions of Nonferrous Metals Society of China》2023年第3期765-776,共12页中国有色金属学报（英文版）

基　　金：the financial supports from the National Natural Science Foundation of China (Nos. 51774125, 52174360);Natural Science Foundation of Hunan Province, China (No. 2020JJ4207)。

摘　　要：采用镁合金在上、钢板在下且添加中间夹层辅助的激光焊接技术,对AZ31B镁合金和DP590双相钢平板试件进行焊接,基于热力学性能和本征力学性质的计算来选择夹层元素,分析添加夹层前后镁/钢接头显微组织和性能的变化。结果表明:添加Sn和Al夹层,接头最大载荷分别为730和590 N,与没有添加夹层相比,分别提高2.04倍和1.46倍;添加Al夹层,接头界面生成脆性较大的Mg_(17)Al_(12)化合物,其限制了镁/钢接头性能提升;而添加Sn夹层,界面生成脆性相对较低的Mg_(2)Sn化合物以及延性Fe_(3)Sn化合物,这是添加Sn夹层镁/钢接头性能高于添加Al夹层的重要原因。The experiments of laser welding were carried out for AZ31B magnesium alloy and DP590 dual-phase steel in an overlap magnesium-on-steel configuration with interlayer addition.The interlayer elements were selected based on the calculation of thermodynamic properties and intrinsic mechanical properties,and the changes of microstructure and properties of magnesium/steel joint were analyzed.The results showed that with the addition of Sn and Al interlayers,the maximum load of the joint was 730 and 590 N,respectively,which was 2.04 times and 1.46 times higher than that without interlayer.With the addition of Al interlayer,the brittle Mg_(17)Al_(12) compound was formed at the magnesium/steel interface,which limited the improvement of the mechanical performance of magnesium/steel joint.In the case of adding Sn interlayers,Mg_(2)Sn with relatively low brittleness and Fe_(3)Sn with a certain ductility were formed at the magnesium/steel interface,which was a vital reason that the properties of joint with Sn interlayer were higher than those with Al interlayer.

关 键 词：异种金属焊接 金属间化合物 力学性能 Sn粉末 Al粉末 

分 类 号：TG456.7[金属学及工艺—焊接]