The role of physical properties in explosive welding of copper to stainless steel

This paper investigates the effects of the physical properties on the microstructure and weldability of explosive welding by joining two metals with a significant contrast in thermophysical properties: stainless steel and copper. Sound welds between stainless steel and copper were obtained, and the interfacial morphology was wavy, regardless of the position of the materials. The weldability of dissimilar pairs was found to be more dependent on the relationship between the physical properties of the base materials than on the absolute value of the material property. When there is a significant difference in thermal conductivity between the flyer and the base plate, together with a material with a low melting temperature, the weldability of the pair is often poor. The relative position of the plates affects the interfacial microstructure even when similar morphologies are found. For the metallic pairs studied, the wave size was bigger for the configuration in which the ratio between the density of the flyer and the density of the base plate is smaller. The same phenomenon was observed for the impedance: bigger waves were found for a smaller ratio between the impedance of the flyer and the impedance of the base plate.