Research on Preparation of Aluminum-Metal Coating and its Microstructure by Melting-Casting

Abstract

A sort of Aluminum-metal coating, which is characterized by a bi-layered structure of Fe2O3+Cr2O3+Al plus NiO+Al layers, was successfully prepared on steel substrate by melting-casting technique. The microstructure, the bonding status of the interface between the coating and the substrate, and the element distribution of the coating were studied. The results indicate that, there is an excellent bonding between the coating and the substrate, and no hole and gap in the composite is found out. Moreover, there is obvious element diffusion in the interface. The coating is composed of block phase, columnar grain, and dendrites. In addition, the elements present a uniform distribution in the interface but an obvious segregation in the middle of the coating.