ABSTRACT
We have developed a process of joining metals and plastics using three-dimensional electrodeposited films of a Ni–Cu alloy. In the present study, the effect of the shape of electrodeposited films, which was changed by using different concentrations of Ni amidosulfate in the Ni–Cu alloy plating solution and by plating at current densities, on the joint strength between stainless steel and polyamide 6 was investigated. The results show that when the concentration ratio of Ni amidosulfate to that of Cu sulfate was 150:15 (g/L) and the plating current density was 10 mA/cm2, a dendritic structure of the electrodeposited film was formed. When the concentration of Ni amidosulfate was 300–450 g/L, dendritic electrodeposited films with thick trunks were formed. When a stainless steel plate with an electrodeposited film and a polyamide 6 plate were joined by heating and compression, voids were formed directly above the dendritic electrodeposited film inside the polyamide 6 plate. A lap joint specimen with the stainless steel plate and polyamide 6 plate joined using the electrodeposited film made of 450 g/L Ni amidosulfate showed an average joint strength of 17 MPa.