Characterization of microstructure and oxidation resistance of Y and Ge modified silicide coating on Nb-Si based alloy

Y and Ge modified silicide coating was prepared on the Nb-Si based alloy by Si-Ge-Y co-deposition at 1300 degrees C for 10 h. It is observed that the coating is composed of an outer layer and a transitional layer. The mass gain of Si-Ge-Y coating is 2.78 mg cm(-2) after oxidation at 1250 degrees C for 100 h. The results indicate that Y refines grains, which can promote the rapid formation of protective SiO2 and GeO2 scale. Therefore, the oxidation resistance of the coating is improved. (C) 2016 Elsevier Ltd. All rights reserved.