冷喷涂Cu涂层辅助铝/钢异种金属电阻热扩散连接工艺分析  

Process analysis on resistance thermal diffusion welding Al/steel dissimilar metals assisted by cold spray Cu coating

作　　者：于江 杜荣茂[2] 范彦龙 葛福琛 余果 张洪涛 杨涛[1] YU Jiang;DU Rongmao;FAN Yanlong;GE Fuchen;YU Guo;ZHANG Hongtao;YANG Tao(Ningbo Institute of Materials Technology&Engineering,Chinese Academy of Sciences,Ningbo,315201,China;State Key Laboratory of Precision Welding&Joining of Materials and Structures,Harbin Institute of Technology,Harbin,150001,China)

机构地区：[1]中国科学院宁波材料技术与工程研究所,宁波315201 [2]哈尔滨工业大学,材料结构精密焊接与连接全国重点实验室,哈尔滨150001

出　　处：《焊接学报》2024年第12期36-44,共9页Transactions of The China Welding Institution

基　　金：国家自然科学基金(U22B20127);国家自然科学基金(52175305);泰山学者建设工程资助(ctstp20230618);济宁市全球揭榜项目(2022JBZP004)

摘　　要：基于冷喷涂技术预先在不锈钢基体表面制备Cu涂层作为中间层,再通过电阻热扩散连接方式与铝合金相连,并借助相关分析测试方法探究Cu涂层厚度对焊接接头界面组织和力学性能的影响.结果表明,冷喷涂预先制备的Cu涂层和不锈钢基体间形成较好的冶金结合,在后续的电阻热扩散连接过程中,Cu涂层作为中间层将原有的铝—钢连接转换为铝—铜连接,有效阻止了Al-Fe相互扩散.当Cu涂层厚度为100μm时,无缺陷的反应层被形成在铝合金和Cu涂层之间,其主要成分为Al(s.s)和少量的Al_(2)Cu,此时接头拉剪载荷最大,为755.39 N,断裂位置位于反应层处,但接头载荷会随Cu涂层厚度增加逐渐降低,这是因为增加的Cu涂层厚度提高接头电阻,形成更高的温度场,导致反应层因生成较多Al-Cu金属间化合物形成裂纹等焊接缺陷.Based on the cold spray technology,the Cu coating was prepared on the surface of the stainless steel substrate as an interlayer in advance,then connected to the Al alloy by resistance thermal diffusion welding.The influence of the thickness of the Cu coating on the interface structure and mechanical properties of the final joint was discussed utilizing relevant analysis methods.The results indicated that a good metallurgical bond was formed between the pre-prepared Cu coating and the stainless steel substrate by cold spray technology.In the subsequent resistance thermal diffusion welding process,the Cu coating acted as an interlayer to effectively prevent the interdiffusion of Al and Fe elements,which was attributed to the interlayer converting the original Al-steel connection into Al-Cu connection.When the Cu coating thickness was 100μm,a defect-free reaction layer was generated between the Al alloy and the Cu coating.The main component was Al(s.s)and a small amount of Al_(2)Cu in the reaction layer.The tensile shear load of the joint reached 755.39 N,and the fracture position was located at the reaction layer.However,the tensile shear load of the joint gradually decreased due to the increase of the Cu coating thickness because the increased Cu coating thickness increased the joint resistance,forming a higher temperature field in the welding process,which led to welding defects such as cracks in the reaction layer due to the formation of more Al-Cu intermetallic compounds.Highlights:(1)A composite method of cold spraying and resistance thermal diffusion welding is proposed to obtain the Al/steel hybrid structure.

关 键 词：冷喷涂 不锈钢 铝合金 反应层 

分 类 号：TG453[金属学及工艺—焊接]