Synthesis and oxidation behavior of (Mo0.97Nb0.03)(Si0.97Al0.03)2 ceramic

(Mo0.97Nb0.03)(Si0.97Al0.03)2 ceramic was synthesized by self-propagating high-temperature synthesis using commercial elemental powders, and then dense monolithic ceramic was prepared via vacuum hot pressing. The oxidation behavior of the bulk ceramic was investigated at 500 °C and 1200 °C. At 500 °C, due to the preferential oxidation of Nb-rich phase and the formation of uniform oxidation layer, the oxidation rate of (Mo0.97Nb0.03)(Si0.97Al0.03)2 is lower than pure MoSi2. At 1200 °C, (Mo0.97Nb0.03)(Si0.97Al0.03)2 shows better oxidation resistance than MoSi2, owing to the uniform complex oxide layer with SiO2, Al2O3 and Nb2O5 formed on the surface of the prepared ceramic.