Effect of annealing on properties of Al/steel composite plates prepared by surface oxidation treatment before cold roll bonding

Al/steel composite plate has a wide application prospect, but great differences in properties between Al and steel are observed. It is difficult to obtain high bonding strength by the traditional cold roll bonding process. Al/steel composite plate was thus prepared by cold roll bonding at a reduction rate of 60% after oxidation treatment on the surface to be composited on the steel side. The heat treatment of holding at 400 °C for 1 h and cooling with the furnace was then adopted. The bonding strength, microstructure, and properties of the Al/steel composite plate before and after annealing were analysed and compared through shear test, bending test, tensile test, and micro-characterization. Results show that the shear strengths of the interface before and after annealing are 100 and 80 MPa, respectively. Although the shear strength of the annealed Al/steel composite plate decreases, the bending and overall tensile properties of the composite plate are improved, showing better mechanical properties.