铝合金与高强钢激光-电弧焊铆复合连接机制研究  

Research on Riveting-laser Arc Welding Hybrid Joining Mechanism of Aluminum Alloy and High Strength Steel

作　　者：韩锐波 王红阳[1,2] 杨帆 刘黎明[1,2] 祝美丽[1,2] HAN Ruibo;WANG Hongyang;YANG Fan;LIU Liming;ZHU Meili(School of Materials Science and Engineering,Dalian University of Technology,Dalian 116024;Key Laboratory of Liaoning Advanced Welding and Joining Technology,Dalian University of Technology,Dalian 116024)

机构地区：[1]大连理工大学材料科学与工程学院,大连116024 [2]大连理工大学辽宁省先进焊接与连接重点实验室,大连116024

出　　处：《机械工程学报》2020年第6期57-64,共8页Journal of Mechanical Engineering

基　　金：上海市重点实验室开放基金(2019001);国家自然科学基金汽车联合基金(U1764251)资助项目。

摘　　要：为实现6061铝合金和Q460高强钢的优质连接,采用激光诱导电弧复合热源对已通过阶梯型铆钉实现预连接的6061铝合金板和Q460高强钢板进行搭接焊试验。分析焊铆复合连接方法下接头的力学性能,断裂模式以及横截面的宏观和微观形貌。结果表明,在铆钉和复合热源的共同作用下,焊铆复合连接接头由3个承载区域组成,分别为钢板和铆钉形成的对接接头,钢板,铆钉以及铝合金板形成的铝-钢连接区以及铆钉侧壁和铝合金板侧壁形成的铝-钢界面。铝-钢连接区的金属间化合物以富Fe的Fe Al相和Fe3Al相为主。在最佳工艺参数下,焊铆复合连接接头的拉剪载荷达到6.2 k N。拉伸断口呈现出纽扣式断裂、母材基体断裂以及拉拔式断裂3种断裂模式,后两种断裂具有更高的韧性和塑性。阶梯型铆钉和激光-电弧复合热源的协同作用可以实现铝合金和高强钢的优质连接。In order to realize the high quality joining of 6061 aluminum alloy and Q460 high-strength steel, the lap welding experiments are carried out on 6061 Al alloy plates and Q460 steel plates which had been pre-joined by multistep rivets by laser induced arc hybrid welding source. The mechanical properties and fracture modes of the hybrid joints are analyzed. In addition, the macroscopic and microscopic morphologies of cross-section of joint are also explored. The results show that the hybrid joint is composed of three loading bear parts under the actions of steel rivet and hybrid welding source, which are respectively the butt joint formed by steel plate and rivet, the Al-steel joint formed by steel plate, rivet and Al alloy plate, and the Al-Fe interface formed by rivet sidewalls and Al alloy plate sidewalls. The intermetallic compounds in Al-steel joint are mainly Fe-rich Fe3 Al phase and Fe Al phase. The hybrid joint had a tensile shear load of 6.2 k N under the optimal parameters. There are three different fracture modes after tensile shear tests:button-type fracture mode, steel base-metal fracture mode and pull-out fracture mode. The latter two show a higher toughness and plasticity. The interaction between stepped rivet and laser-arc hybrid welding source enable a high quality joining between Al alloy and high-strength steel.

关 键 词：高强钢 铝合金 铆钉 复合连接 力学性能 界面 

分 类 号：TG457[金属学及工艺—焊接]