Numerical simulation of the joining interface of dissimilar metals in vaporizing foil actuator welding: Forming mechanism and factors

Abstract Predicting and controlling the joining interface are the main difficulties in impact welding dissimilar metal. In this study, the smoothed particle hydrodynamics (SPH) method was used to simulate the Cu/Ti wave interface forming process during high-rate impact welding. This process simulation was verified by vaporizing foil actuator welding experiments. The forming mechanism and factors influencing the characteristics of joining interface were simultaneously investigated. Results showed that, joining interface wave forming depended on the density ratio of the flyer sheet to the target sheet. Wave formation distance was mainly related to materials yield stress. The wavelength and amplitude of wavy characteristic increased with the impact angle and impact speed. Temperature distribution analyses proved that the average temperature of the vortex at the welding interface was higher than that in the other areas, indicating that the inter-metallic distribution was mainly in the vortex of the wave interface. Investigation of the moving trail of metal particles verified that the interaction of interface materials was caused by embedded deformation.