气载钎剂辅助钢/铝激光熔钎焊工艺与组织  

Technology and Microstructure for Laser Welding-brazing Assisted by Transporting Flux with Shielding Gas between Steel and Aluminum

作　　者：喻高扬 陈树海[1] 黄继华[1] 杨健[1] 赵志毅[1] YU Gaoyang;CHEN Shuhai;HUANG Jihua;YANG Jian;ZHAO Zhiyi(School of Materials Science and Technology Beijing,University of Science and Technology Beijing,Beijing 100083)

机构地区：[1]北京科技大学材料科学与工程学院,北京100083

出　　处：《机械工程学报》2020年第6期50-56,共7页Journal of Mechanical Engineering

基　　金：国家自然科学基金(51875037);北京市自然科学基金(3192021);中央高校基本科研业务(FRF-GF-18-004B)资助项目。

摘　　要：为解决钢/铝异种金属熔钎焊过程中液态金属铝在固态钢表面润湿性差的问题,提出一种气载钎剂辅助钢/铝异种金属激光熔钎焊的新方法。采用不锈钢与5052铝合金作为母材,分别进行激光填丝与无丝搭接熔钎焊试验。研究焊接线能量对接头润湿角、接头力学性能的影响,分析有无焊丝情况下接头典型微观组织。结果表明,气载钎剂辅助不锈钢/铝合金异种金属激光熔钎焊能有效解决液态金属在不锈钢表面的润湿铺展性问题。填丝搭接熔钎焊得到的接头润湿角最小值为37°,接头拉伸强度最大达到132.8 MPa,约为铝合金强度(211.7 MPa)的62.7%;无丝搭接熔钎焊得到的接头润湿角最小值为18.8°,接头拉伸强度最大达到109.2 MPa,约为铝合金强度的51.6%。在填丝、无丝焊接时,钢侧界面均会形成Fe2Al5与Fe Al3两层金属间化合物(Intermetallic compounds,IMCs)。In order to solve the problem of poor wettability of liquid metal on the surface of stainless steel, a new method of powder flux transported by shielding gas is proposed to assist laser welding-brazing process. Laser welding-brazing of 5052 aluminum alloy and stainless steel with/without filler wire is carried out. Influence of welding heat input on wetting angle and mechanical property is studied. The typical microstructure of the joint with/without filler wire is analyzed. The results show that the laser welding brazing assisted by transporting flux with shielding gas for stainless steel/aluminum alloy dissimilar metals could improve wettability of liquid metal on stainless steel effectively. When the filler wire is used, the wetting angle of the joint is 37 degree. The tensile strength of the joint is about 132.8 MPa, which is about 62.7% of the strength of the aluminum alloy(211.7 MPa). In absence of filler wire, the wetting angle of the joint is 18.8 degree. The tensile strength of the joint is about 109.2 MPa, which is about 51.6% of the strength of the aluminum alloy. Two intermetallic compounds(Fe2 Al5 and Fe Al3) will be form at the steel side interface with or without filler wire.

关 键 词：钢/铝连接 激光熔钎焊 焊接工艺 微观组织 

分 类 号：TG456[金属学及工艺—焊接]