Local dynamic effects on impact welding process window variability

Joining metallic materials with dynamic welding techniques (e.g. impact welding) provides a means to metallurgically bond material via mechanical mixing, extreme deformation rates, and local material instability. Process variables of interest include the selected metals, dimension, impact velocity, and impact angle. Even with limited process variables and relatively simple boundary conditions, local dynamic effects arise from the complexity of the wave propagation events, which can lead to material state evolution which modifies process windows. This talk presents a computational analysis of local wave dynamics present in vaporizing foil actuator welding (VFAW), comparing hydrocode simulation results with experimental observations of impact weld properties. Local conditions leading to instability and weld thickness will be analyzed and compared with experiments as a function of material selected, impact velocity, and impact angle. Process window variability is discussed in this context and presented for similar and dissimilar materials.