Evaluation of Joint Strength and Process Parameters in Aluminium-Stainless Steel by Electromagnetic Pulse Welding

Electromagnetic pulse welding (EMPW) is a solid-state joining technique for similar and dissimilar metals. In present work, analysis of the joining between aluminium (AA6061) and stainless steel (SS316) is attempted. A numerical analysis is carried out to establish the relation between electromagnetic and mechanical parameters such as current density, magnetic field, lorentz force, velocity, temperature, and load-bearing capacity. The aluminium alloy tube is joined with the steel rod at varying operating parameters such as voltage (19 and 20 kV), energy (30 and 36.1 kJ), capacitance (150 and 200µF), stand-off distance (1.0, 1.5, 2.0, and 2.5 mm). The joint strength of 114 MPa was obtained at 2.0 mm SOD for 30 kJ of energy and 460 m/sec of impact velocity. Microstructural analysis confirms the formation of wavy and micro-porous interfaces. A severe plastic deformation causes the localized melting of the interface, leading to intermetallic phase formation. A high hardness of ~ 520HV_0.5 was observed at the interface as compared to base metals. A leak-proof test using the hydraulic pressure technique shows no leakage at 100 kg/cm² pressure.