铝合金/不锈钢双光束激光深熔焊接接头组织及力学性能  

MICROSTRUCTURES AND MECHANICAL PROPERTIES OF DUAL-BEAM LASER KEYHOLE WELDED JOINTS OF ALUMINUM ALLOYS TO STAINLESS STEELS

作　　者：潘峰[1] 崔丽[1] 钱伟[1] 贺定勇[1] 魏世忠[1] PAN Feng CUI Li QIAN Wei HE Dingyong WEI Shizhong(School of Materials Science and Engineering, Beijing University of Technology, Beijing 100124, China)

机构地区：[1]北京工业大学材料科学与工程学院,北京100124

出　　处：《金属学报》2016年第11期1388-1394,共7页Acta Metallurgica Sinica

基　　金：国家自然科学基金项目51475006;北京市教育委员会科技计划重点项目暨北京市自然科学基金B类项目KZ201610005004资助~~

摘　　要：采用双光束光纤激光热源对1.5 mm厚5083铝合金和1.8 mm厚304不锈钢异种合金搭接接头进行了激光深熔焊接工艺实验,研究了光束相对位置对接头焊缝成形、界面组织及接头力学性能的影响.结果表明,在无任何填充材料条件下,采用双光束激光进行铝合金/不锈钢异种合金激光深熔焊接能够获得良好的焊缝表面成形,小能量分光束在前的接头界面金属间化合物(IMC)厚度相对较薄.接头界面纳米硬度测试结果表明,IMC层平均硬度为9.61 GPa,且明显高于不锈钢母材(4.12 GPa)和铝合金母材(1.09 GPa).接头拉伸断裂于铝合金/不锈钢IMC界面层.小能量分光束在前的接头获得机械抗力大于分光束在后的接头.Aluminum alloy and steel thin sheets have been mostly used in the automotive industry to get a lightweight car body. Nowadays several studies are focused on the joining of aluminum alloy to steel by new weld- ing methods especially by laser welding. In this work dual-beam fiber laser keyhole welding was introduced to joining of 1.5 mm-thick aluminum alloys to 1.8 mm-thick 304 stainless steels in an overlap joint configure. The influences of different laser focusing positions on the weld appearance, interface microstructures and tensile mechanical resistance of the welded joints were studied. As a result, the good weld appearance of the aluminum alloy to stainless steel joints were obtained by dual-beam fiber laser keyhole welding process without any filler materials. The thickness of the intermetallic compound layer of the joint interface is comparatively thin when the laser beam with low energy is focusing on the front. The nano-hardness testing results show that the average hardness of intermetallic compound layer is 9.61 GPa, which is significantly higher than that of the parent stainless steel of 4.12 GPa and aluminum alloy of 1.09 GPa. The fracture of the welded joints occurs on the aluminum alloy/stainless steel interface layer. The highest mechanical resistance of 131 N/mm can be obtained by the low energy laser beam focused on the front.

关 键 词：铝合金/不锈钢异种合金 双光束 激光深熔焊 金属间化合物(IMC) 

分 类 号：TG456.7[金属学及工艺—焊接]