文档介绍：Trans. Nonferrous Met. Soc. China 24(2014) 989995Microstructures and properties of welded joint of aluminum alloy togalvanized steel by Nd:YAG laser + MIG arc hybrid brazing-fusion weldingGuo-liang QIN, Yu-hu SU, Shu-jun WANGKey Laboratory for Liquid-Solid Structure Evolution and Processing of Materials, Ministry of Education,Shandong University, Ji’nan 250061, ChinaReceived 8 April 2013; accepted 15 January 2014Abstract: According to the differences in melting point between aluminum alloy and steel, 6013-T4 aluminum alloy was joined togalvanized steel by large spot Nd:YAG laser + MIG arc hybrid brazing-fusion welding with ER4043(AlSi5) filler wire. Themicrostructures and mechanical properties of the brazedfusion welded joint were investigated. The joint is divided into two parts offusion weld and brazed seam. There is a zinc-rich zone at fusion weld toe, which consists of α(Al)Zn solid solution and AlZneutectic. The brazed seam is the FeAl pounds (IMCs) layer of 24 μm in thickness, and the IMCs include FeAl2,Fe2Al5 and Fe4Al13. FeAl2 and Fe2Al5 are located in pact reaction layer near the steel side, and Fe4Al13 with tongue shape orsawtooth shape grows towards the fusion weld. The tensile strength of the joint firstly increases and then decreases as the weldingcurrent and laser power increase, the highest tensile strength can be up to MPa, and the fracture usually occurs