Interfacial Microstructure and Mechanical Properties of Al5052/Mg-9.5Li-2Al Alloy Clad Plates

Al5052/Mg-9.5Li-2Al alloy clad plates were fabricated by cold rolling and the effect of annealing temperature on the microstructures and mechanical properties were investigated. Results show that no defects like cracks or voids are found at the bond interface in the annealed clad plates. Intermetallic layers are formed at the clad plate bond interface after annealing at and above 623 K. The main phases across the bond interface are α-Mg+β-Li, Mg17Al12, Li-dissolved Al3Mg2 and α-Al in sequence from the Mg-9.5Li-2Al base plate to Al5052 cover plate. The bond strength increases with increasing of annealing temperature below 623 K. When annealed at 623 K, the interfacial normal bond strength of the clad plates attains its maximum 17.83 MPa, with excellent ductility of an elongation of 18.7%, and no debonding is observed in the tensile specimen. When annealed at 673 K, the tensile property of the clad plates worsens due to interface debonding.