Improvement of cyclic oxidation resistance of Y-containing Ti-6Al-2.5Sn-4Zr-0.7Mo-0.3Si alloys

The cyclic oxidation behavior of Y-containing Ti-6Al-2.5Sn-4Zr-0.7Mo-0.3Si alloys was studied at 650-750 °C. The oxidation kinetics of the alloys was investigated by measuring weight gains at different temperatures. The microstructure characterization of the alloys was carried out using XRD and SEM. It was found that oxidation resistance of the alloys at 650-750 °C is improved by Y-addition. The excellent oxidation resistance obtained in the Y-containing alloys is mainly attributed to the significant refinement of oxides and consequently retarding the inward diffusion of oxygen. Y addition is also found very effective in improving the adhesion between oxidation layer and matrix.