Fabrication of pure Al/Mg-Li alloy clad plate and its mechanical properties

Pure Al/Mg-Li alloy clad plates were fabricated by the cold rolling method and their mechanical properties of annealed plates were investigated as a function of annealing temperature. No defects like cracks or voids including Kirkendal voids are observed at the joint interface in the annealed clad plates. On annealing at and above 523 K, reaction phases are formed at both pure Al and Mg-Li sides at the joint interface. The reaction phases are estimated by EPMA analysis to be Al3Mg2 in the pure Al side and highly concentrated Mg phase in the Mg-Li side. The formation of the intermetallic phase induces microcracking and macroscopic fracture in 180° bending test and tensile test. In contrast, the clad plates annealed at 423 and 473 K, which show no indication of a reaction phase, exhibit excellent formability by the 180° bending test and no debonding in the tensile test.