Interface characteristics and performance of magnetic pulse welded copper-Steel tubes

An attempt has been made to join two tubes of pure copper and low carbon steel by magnetic pulse welding in lap joint configuration. Satisfactory welds were obtained with an optimal set of parameters consisting of discharge energy, standoff distance and initial collision angle. The welded interface revealed a wavy morphology with pockets of intermixed metal vortices. High resolution electron microscopy and microanalysis showed the formation of nano-grains along the interface and evidence of short distance interatomic diffusion across the weld joint respectively. The strain hardening effect due to high energy impact led to significantly higher microhardness on the steel side of the interface. Torsion tests confirmed acceptable joint strength as failure took place in the copper base material.