Copper/stainless steel cladding by explosive welding: effect of the energetic mixture

Copper/stainless steel clads are very appealing for numerous industries by combining their specific properties into a single component. This study investigates the production of these clads by explosive welding, emphasising the influence of varying energetic substances and parameters on the interfacial morphology, mechanical properties, and overall quality of the welded joints. Two weld series were produced using different energetic mixtures, one with a higher density and a detonation velocity of 2420 m.s−1 and the other with a lower density and a detonation velocity of 3320 m.s−1. Successful clads were achieved, allowing the production of components with a very good mechanical behaviour without the use of expensive interlayer plates. The clads produced with the higher detonation velocity mixture, which provided a lower explosive ratio and a lower impact velocity, presented a smoother surface finish with fewer irregularities. In terms of weld interface morphology, interfaces composed of well-defined waves with a typical morphology were achieved for both series. The wavelength and amplitude were found to vary according to the used energetic mixture, as they depend on the impact velocity, the explosive ratio, and the energy lost in the collision. The tensile-shear tests yielded excellent results, with welded joints demonstrating superior strength compared to the parent materials, as evidenced by fracturing occurring outside the weld region. The interfacial hardening of the welds was influenced by the energetic mixture, contributing to an improvement in the clad maximum tensile-shear load.