Microstructure and mechanical properties of dissimilar joint between aluminum and aluminum-coated steel by cold metal transfer process  

作　　者：田春英 周智远 王军 廖平 李海涛 庄明辉 杨文杰 

机构地区：[1]School of Material Science andEngineereing, Jiamusi University, Jiamusi, 154007

出　　处：《China Welding》2015年第3期73-80,共8页中国焊接（英文版）

基　　金：This research is supported by the National Natural Science Foundation of China （ No. 51005101 ）, Jiamusi University Scientific Research Project （12010 -118） and State Key Laboratory of Advanced Welding Production Technology Project （AWJ-M13 -04）.

摘　　要：Two dissimilar materials, aluminum alloy and aluminum-coated steel, were joined by cold metal transfer process using AlSi5 filler wire. To this end, the steel was coated with Al-Si. The steel did not melt and aluminum was melt to form the joint during the process, it was actually cold metal transfer welding-brazing. The macrostructure, microstructure, alloy element distribution, and inter-metallic compounds were analyzed by optical microscopy, scanning electron microscopy, and energy dispersive spectroscopy. It was found that the Al-Si coating dissolved into the weld metal. The pre-existing thin Fe-Al- Si ternary inter-metallic compounds in the interface between the Ak-Si coating layer and base metal steel also partially dissolved into the weld zone, tending to reduce the thickness of inter-metallic compounds. Approximate 3 μm thick undissolved intermetallic compound was found at the interface after welding which could guarantee sound bonding strength in dissimilar materials joining. The sample was fractured at the fusion zone near the aluminum side in the tensile test. The ultimate tensile strength was about 156 MPa, and the fracture mode is ductile failure in nature according to its morphology.Two dissimilar materials, aluminum alloy and aluminum-coated steel, were joined by cold metal transfer process using AlSi5 filler wire. To this end, the steel was coated with Al-Si. The steel did not melt and aluminum was melt to form the joint during the process, it was actually cold metal transfer welding-brazing. The macrostructure, microstructure, alloy element distribution, and inter-metallic compounds were analyzed by optical microscopy, scanning electron microscopy, and energy dispersive spectroscopy. It was found that the Al-Si coating dissolved into the weld metal. The pre-existing thin Fe-Al- Si ternary inter-metallic compounds in the interface between the Ak-Si coating layer and base metal steel also partially dissolved into the weld zone, tending to reduce the thickness of inter-metallic compounds. Approximate 3 μm thick undissolved intermetallic compound was found at the interface after welding which could guarantee sound bonding strength in dissimilar materials joining. The sample was fractured at the fusion zone near the aluminum side in the tensile test. The ultimate tensile strength was about 156 MPa, and the fracture mode is ductile failure in nature according to its morphology.

关 键 词：cold metal transfer WELDING-BRAZING ALUMINUM aluminum-coated steel 

分 类 号：TG146.23[一般工业技术—材料科学与工程] TG146.21[金属学及工艺—金属材料]