Improved impact toughness of laminate heterogeneous AZ31/GW103K alloys by interface delamination

Abstract

An AZ31/GW103K (AG) laminate heterostructured material was fabricated by diffusion bonding. The impact resistance of AG was evaluated by Charpy notched impact testing and the fracture mechanism was systematically studied. The impact toughness of AG is nearly twice of the homogeneous structured AZ31 or GW103K. The delamination can effectively prevent crack initiation and propagation under the high-speed impact, which significantly improves the overall impact toughness by consuming high impact energy. Simultaneously, the cracks crossing over the Al2(Gd, Y) zone at the interface consume considerable impact energy. Besides, the conventional thermal strain, composition diffusion, and the mechanical incompatibility of AG can also consume energy by coordinating plastic deformation. During impact, the primary deformation mechanism of the GW103K layer is {0001} basal plane slip. While the AZ31 layer is relatively complicated, primarily of twinning, multiple dislocation slip, and stacking faults.