Laser-roll welding of dissimilar metals of low carbon steel and aluminum alloy

In order to solve the problem of the low welded joint properties by the traditional welding of low carbon steel SPCC/aluminum alloy A5052 dissimilar metals, laser roll welding of dissimilar metals of low carbon steel to aluminum alloy A5052 was performed based on 3 kW diode laser robot welding system, and the proper welding parameters were obtained. The characteristics of intermetallic compounds(IMC) at the interface layer were investigated by laser microscope, electron probe micro-analyzer(EPMA). The properties of the joint such as hardness and tensile strength were tested. The results showed that the IMC in the interface layer consists of ductile IMC(including Fe₃Al and FeAl) and brittle IMC(including FeAl₃, FeAl₂, Fe₂Al₅). The thickness of IMC was about 8-10μm. the highest strength of about 210 MPa was reached, while the thickness of ductile interface laye was nealy about 1.8μm.