Experimental and Numerical Research on the Laser Impact Welding of Ti/SS

Abstract

The welding of Ti/SS metal foil was realized by laser impact welding. The interface morphology and mechanical properties of welding specimens were studied by systematic experiments, and the experimental phenomena were revealed by smoothed particle hydrodynamics numerical simulation. Results indicated that the plastic deformation of the composite plate and the springback of the welding spot center were small under low laser pulse energy and enlarged under high laser pulse energy. Impinging jet, interface wave, and interface cracking were found at the micro-interface of the welding specimens. Increasing the laser pulse energy resulted in the transition of the interface waveform from straight to microwave and finally to wave primarily because of the change in interfacial impact pressure and effective plastic strain. Energy dispersive spectroscopy analysis showed that the trace element diffused at the welding interface, and no intermetallic compounds were formed. SPH simulation revealed that the thickness of the high-temperature layer was related to the thickness of the diffusion layer. As the distance between the test point and welding interface increased, the hardness decreased. The maximum tensile force of the welding specimens increased with laser pulse energy. The failure mode of the interface was welding spot edge fracture failure.