Novel resistance element welding of Al alloy to boron steel

A novel resistance element welding (REW) technology was applied to join 6061 Al alloy to 22MnMoB boron steel. In REW process, a technological hole was drilled previously in Al sheet, and then a Q235 steel rivet was inserted into the hole. Resistance spot welding (RSW) was carried out in the location of rivet. The mechanical properties, fracture morphology and microstructure of resistance element welded joint were investigated and compared to those made by traditional resistance spot welding joints. The results show that RSW could barely join Al 6061 to boron steel, but the novel REW technology could realize reliable joining of these two materials. The maximum tensile shear load of joint was 7 142 N, and the toughness of joint was also satisfied.