Effect of Copper Foil Interlayer on the Interfacial Microstructure and Properties of 1060Al/AZ31 Composite Plates Rolled by Heated Roll

Laminated Al/Mg composite plates have broad application prospects in the field of structural lightweighting. This study prepared laminated 1060Al/AZ31 composite plates using copper foil as an interlayer, employing rolling process by heated roll. The research investigates and analyzes the changes in interfacial microstructure and properties of the composite, as well as the texture distribution in the deformation-resistant Mg alloy layer, under varying copper foil thicknesses and annealing conditions. The results indicate that at the Al matrix and Cu foil interface, intermetallic compounds such as Al2Cu, AlCu, and Al4Cu9 are formed sequentially from the Al side, while at the Mg matrix and Cu foil interface, a solid solution is formed. The apparent activation energies calculated for the growth of the total intermetallic layer, Al2Cu + Al4Cu9 and Al2Cu layers were about 50.11, 50.39 and 48.72 kJ/mol, respectively. As the thickness of the Cu foil increases, the variation in deformation uniformity at the interface causes the grain orientation of the Mg layer to first strengthen and then weaken. The composite sheet with a Cu foil thickness of 0.06 mm exhibits the most uniform microstructure and optimal comprehensive mechanical properties when annealed at 300 degrees C for 1 hour after rolling.