Effect of impact velocity on interface formation in aluminum/galvanized steel plate high-speed impact joining

High-speed impact joining, as an advanced solid-state welding technology, demonstrates unique advantages in joining dissimilar metals. The ultrafast transient characteristics interface formation poses significant challenges for characterizing the welding process. In this study, a FEM-SPH coupled numerical simulation method is employed to reveal the wave formation process at the aluminum/galvanized steel interface under foil vaporization impact conditions. Through systematic simulations of graded impact velocities, the wave formation behavior is quantitatively characterized. The results indicate that the FEM-SPH algorithm effectively simulates the interface wave formation process. Increasing the impact velocity enhances wave parameters under certain conditions. When the velocity exceeds a threshold, localized peeling of the galvanized layer occurs at the wave trough, resulting in direct aluminum-steel contact. These findings provide theoretical guidance for optimizing impact welding parameters in automotive lightweight applications.