铜对钢/铝激光-MIG复合焊接头组织及性能的影响  

Effects of Cu on microstructures and properties of laser-MIG hybrid welded joint of steel/aluminum

作　　者：马骁[1] 孙大千[1] 段珍珍[2] 谷晓燕[1] 李洪梅[1] 

机构地区：[1]吉林大学教育部汽车材料重点实验室,长春130025 [2]长春工程学院机电工程学院,长春130012

出　　处：《焊接学报》2016年第12期41-44,共4页Transactions of The China Welding Institution

基　　金：国家自然科学基金资助项目(51275204)

摘　　要：采用激光-MIG复合焊方法研究了铜对SYG960E超高强度钢/6061铝合金焊接接头微观组织及力学性能的影响.结果表明,与MIG焊相比,激光-MIG复合焊有利于改善焊缝成形及焊接质量.钢/铝界面层具有双层结构,靠近铝焊缝侧为针状的FeAl_3金属间化合物,而靠近钢母材侧为条状的Fe_2Al_5金属间化合物.铜对钢/铝界面层及接头的力学性能具有显著的影响.添加铜后可以有效地减小界面层厚度和裂纹敏感性,降低钢/铝接头的最高硬度,明显提高接头的抗拉强度,接头强度可以提高110%,这主要与铜抑制界面层生长和改善界面层中Fe-Al金属化合物的脆硬性有关.Effects of Cu on microstructures and mechanical properties of laser-MIG hybrid welded joint of SYG960E ultra-high strength steel to 6061 aluminum were studied.The experimental results showed that compared with MIG welding,laser-MIG hybrid welding was beneficial to improve the weld appearance and welding quality.The interface layer of steel and aluminum has a double-layer structure consisting of needle-like FeAl_3 intermetallic compound at aluminum side and strip-like Fe_2Al_5 intermetallic compound at steel side.The Cu has great effect on the interface layer and mechanical properties of steel-Al joints.When the Cu is added,the thickness of interface layer,the crack sensitivity and maximum micro-hardness of steel-Al joints will be decreased,and the tensile strength of steel-Al joints will be increased by 110%.It is related to that Cu can restrain the growth of interface layer and decrease the brittleness of Fe-Al intermetallic compounds in the interface layer.Therefore,the addition Cu is an effective way to improve the microstructures and mechanical properties of laser-MIG hybrid welded joints of ultra-high strength steel to aluminum.

关 键 词：激光-MIG复合焊 超高强度钢 铝合金 微观组织 力学性能 

分 类 号：TG457.1[金属学及工艺—焊接]