Resistance spot welding study of 5052 Al alloy and DP600 automobile steel using Ni interlayer

采用Ni中间层的5052铝合金/DP600车用钢电阻点焊研究 Resistance spot welding study of 5052 Al alloy and DP600 automobile steel using Ni interlayer 李佳 LI Jia 1 first-author 陈地群 CHEN Diqun 1 冉启洪 RAN Qihong 1 岳林 YUE Lin 1 汪维登 WANG Weideng 1 钟海平 ZHONG Haiping 1 重庆长安汽车股份有限公司 重庆长安汽车股份有限公司 Chongqing Changan Automobile Co.,Ltd. Chongqing Changan Automobile Co.,Ltd. 采用Ni做中间层实现了5052铝合金和DP600车用钢的电阻点焊连接,借助扫描电镜和拉伸-剪切实验对接头界面组织和连接强度进行了表征和评价。结果表明,在点焊过程中,Ni中间层未发生熔化,完全阻隔了铝合金和钢母材之间的冶金反应。在铝合金/中间层界面,生成了Al3Ni金属间化合物层,冶金结合良好。在Ni中间层/钢界面,主要通过固态扩散形成Fe-Ni固溶体实现连接,但存在大量的未焊合区。随着焊接电流增大,未焊合区面积逐渐减少。接头连接强度随焊接电流增大而显著提升,在焊接电流11 kA时接头最大载荷达到4.3 kN。 Resistance spot welding of 5052 Al alloy and DP600 automotive steel is realized by using a Ni interlayer.The interfacial microstructure and mechanical properties ofjoints are investigated by SEM and tensile-shear test.The results show that the Ni interlayer remains integral during the welding process and completely suppresses the interaction between Al alloy and steel base metal.Robust metallurgical bonding is achieved at the Al/Ni interlayer interface by forming Al 3 Ni intermetallic phase.Joining at the Ni interlayer/steel interface is realized by formation of Fe-Ni solid solution via solid state diffusion bonding.However,considerable amount of unbondedzoneexists.The bonding area improves by elevating the welding current.Bonding strength appreciably enhances as welding current increases.The maximum tensile-shear loading of 4.3 KN is obtained at welding current of 11 KA. 铝合金 DP600 电阻点焊 Ni中间层 金属间化合物 Al alloy DP600 resistance spot welding Ni interlayer intermetallic TG453.9 国家重点研发计划（2016YFB0101700） 2022-03-08 12 50