Microstructure and Mechanical Properties of Explosive Weld Copper-Mild Steel Joint

Mild steel and copper was joined with explosive welding using suitable parameters to obtain a copper-mild steel joint of high integrity. There was no diffusion, melting and formation of intermetallic zone between the bonded plates. An inter-mixed zone of the base materials is observed with a span of 1300 μm around the interface. Significant hardening and softening of the microstructure was observed on the copper and steel sides around the interface respectively by inter-mixing effect arising out of mechanical inter-locking. Shear strength of the joint (260 MPa) was quite higher with respect to that of the copper, the weaker metal of the copper-mild steel bimetal combination. Reasonably ductile shear failure occurred in the copper plate, and no failure was observed along the interface.