Experimental and Numerical Analysis of Formation Manner of Characteristic Wavy Morphology in Impact Welded Similar- and Dissimilar-Metal Plates

The characteristic wavy interface was observed in the impact welded similar- and dissimilar-aluminum lap joints. In the present study, effects of impact conditions such as collision velocity, collision angle and materials combination on the interface morphology were investigated. The numerical simulations of the oblique collision between metal plates were performed by using smoothed particle hydrodynamic (SPH) method. The simulation could visualize the formation process of the wavy interface successfully. The wave size increased with increasing collision velocity. The interface of similar-metal joint exhibited the well-proportioned sinusoidal morphology. On the other hand, that of dissimilar joint was asymmetric wave with vortices. Occurrence of two different interface instabilities at the collision point is plausible, and the density difference is considered to control which one of them is dominant. Various joints were also fabricated by magnetic pulse welding and explosive welding. Their interface morphology agreed well with the simulation results.