High temperature oxidation of disilicides in the system MoSi2TiSi2

Abstract The oxidation behaviour of silicon ceramics e.g. MoSi2 at temperatures up to 1600°C is due to the formation and stability of glassy SiO2-surface layers. The oxidation behaviour of two-component silicides is a function of crystallization and segregation phenomena in the oxidic surface layer. Small amounts of titanium in the SiO2-layer lead to devitrification of the glass resulting in low O2-transport. But with high Ti content in the MoSi2 different oxides (TiO2 and SiO2) are formed isolated and therefore the oxidation rate increases rapidly.