Characteristics of ultrasonic spot welding of Cu/Ni dissimilar metals

Abstract

With increasing clamping pressure, the bond density increases, the effective thickness decreases, and the plastic deformation at the Cu side near the welding interface regions below the sonotrode tip peak and valley increases; the maximum lap shear tensile load is obtained at the clamping pressure of 0.5 MPa. In the case of the Cu/Ni joint prepared at the clamping pressure of 0.5 MPa, evident mutual diffusion and nanoscale wave-like pattern appear in the Cu/Ni interfacial area, bonding between Cu and Ni sheets is formed by the interdiffusion of the parent elements. Plastic strain distribution and temperature on weld cross-section were simulated employing finite element analysis.