Morphology and structure of high temperature MoSi2 coating on niobium

The high-temperature oxidation-resistant MoSi2 coating on the Nb substrate was prepared by slurry firing. The structure, compositions and phase distribution of the coating and the relationship between these features and the oxidation resistance of the coating were investigated by SEM, EDS and XRD. The results indicate that the interface between the coating and the substrate has metallurgie combination, and a transitional layer is formed by diffusion. The multi-layer structure improves the oxidation resistance of the coating. The method of slurry firing to prepare the high-temperature MoSi2 coating on Nb is feasible. The SiO2 scale, which is formed on the surface of the coating by the self-oxidation of MoSi2, prevents the further diffusion of oxygen.