Experimental and Numerical Investigations on the Interface Characteristics of Laser Impact-Welded Ti/Brass Joints

Abstract

The dissimilar welding of metal Ti and alloy brass foils was achieved via laser impact welding. Three laser energies were used, and the interface characteristics of Ti/brass joints were systematically investigated through experiments and smoothed particle hydrodynamics (SPH) simulation. Results indicated that the Ti/brass interfaces under all three laser energies were ring-shaped, and the increase in laser energy resulted in the increase in effective welding area. The phenomena of jet, interface waveform, and cracking were observed at the interface. Jet particles were released from both the Ti flyer and brass target, and interfacial elemental diffusion occurred. SPH simulation results showed that the generation of the interface waveform was related to the collision point position and jet particle ejection direction. The size of the interface waveform increased with the laser energy and increased along the welding direction. This finding was correlated with the horizontal welding velocity, jet velocity, and normal stress. Three different interface failure modes were included in the tensile shear tests, and the maximum tensile force of Ti/brass joints increased with the laser energy.