Isothermal oxidation behavior of high-Nb-containing TiAl alloys doped with W, B, Y, and C/Si

Abstract

The isothermal oxidation behavior of high-Nb-containing TiAl alloys doped with W, B, Y, and C (WBYC) /Si (WBYS) was investigated via oxidation tests at 900 °C in ambient air. Both alloys exhibited outstanding high-temperature oxidation resistance, with unit weight gains of < 1 mg/cm2 after 200 h of oxidation at 900 °C. The inclusion of alloying elements could refine the crystalline particle size and reduce oxygen activity, consequently suppressing TiO2 growth and promoting Al2O3 formation. Furthermore, the generated oxide pegs improved the adhesive strength between the oxide scale and the substrate and the spalling resistance of the oxide scale.