Microstructure of Aluminum Bronze Coating Sprayed by Cold Gas Dynamic Spraying (CGDS)

Cold Gas Dynamic Spraying (CGDS) has been developed to fabricate surface coating as a new technique in recent years. In this paper, aluminum bronze particles were sprayed on 45 steel and 316L stainless steel by CGDS, and the coating was sucessfully fabricated on the surface of the steels. The microstructure of the coating and the interface between the coating and the substrate were investigated by scanning electron microscope (SEM), energy dispersive (EDX) and XRD. It was found that the coating was dense and its porosity was low, while the microhardness of the coating was lower than that of the bulk one; Mechanical bonding was the main formation mechanism of the coating, and there was metallurgical bonding too; Diffusion occured at the interface between the coating and substrate; a phase in aluminum bronze particles transformed to p phase after the spray and the transformation was induced by the plastic strain during spraying.