Microstructure and mechanical performance of induction-pressure welding joints interface between Q235 steel and 5052 aluminium alloy

In order to realize the efficient connection between steel and aluminum alloy on vehicle body, a novel welding method—induction-pressure welding (IPW) was presented. The chemical compositions, intermetallic compounds, micro-structure and hardness on interface between Q235 steel and 5052 aluminum alloy after IPW process were tested by optical microscope, scanning electron microscopy, X-ray diffraction and microhardness tester. The results showed that the connection between Q235 steel and 5052 aluminum alloy can be realized by IPW process. The thickness of the intermetallic compound of No.1 and No.2 samples is approximately 115 μm and 85 μm, respectively. The morphology of interface microstructure is saw-tooth formation and the tooth tip is pointed towards the steel. The hardness of joints interface microstructure is higher than that of matrix for steel and aluminum alloy. The tensile strength of the No.1 and No.2 samples joint is 49 MPa and 158 MPa, respectively. Meanwhile, the thickness of intermetallic compound decreases linearly with the decrease of heating temperature during IPW process. In addition, the diffusibility of aluminum atom is higher than that of iron atom. The intermetallic compound with aluminum-rich such as Fe₂Al₅ and FeAl₂ will be formed on interface between steel and aluminum alloy during IPW process.