Forming characteristics of Mg/Al laminates by pre-rolling corrugated interface process

The conventional flat rolling (FR) process suffers from low bonding strength and significant edge cracks when preparing Mg/Al laminates. This paper proposes a Lattice Severe Deformation Pre-Rolling (LSDPR) corrugated interface scheme and compares it with the FR process. The forming characteristics of Mg/Al laminates prepared using the LSDPR process were investigated through experimental and simulation methods. The results show that the bonding interface of Mg/Al laminates prepared by LSDPR exhibits an obvious three-dimensional network of corrugations. Compared to the FR process, the bonding area at the interface increases, and multiple cross-shear bands are formed. This accelerates the cracking of metal oxide film, the forming of the hardened layer at the interface and the diffusion of elements. Furthermore, the waveform structure provides a mechanical interlocking effect, significantly enhancing the bonding strength. The trough positions of Mg/Al laminates prepared by LSDPR exhibit the highest shear strength, with values of 58.81 MPa and 55.93 MPa along the transverse direction (TD) and rolling direction (RD), respectively. These values are 52.5% and 78.4% higher than the shear strengths of 38.56 MPa and 31.34 MPa in the FR process. Additionally, the LSDPR process helps suppress edge cracks in the magnetism alloy plate. The corrugated structure along the TD inhibits the inward propagation of edge cracks, and the structure along the RD distributes the damage, making the edge damage at the peak lower than that at the trough, which effectively prevents the initiation and expansion of edge cracks. The proposed LSDPR process provides a valuable reference for the roll forming of high-quality metal laminates.