| Abstract Scope |
Refractory alloys are proposed for hot section components of turbine engines to increase operating temperatures beyond those achieved with Ni-base alloys, however, they are prone to rapid oxidation. Recent developments demonstrate that thermally grown CrNbO4 and CrTaO4 offer improved protection of refractory alloys compared to binary metal oxides, however, the stability of these complex oxides in water-vapor containing combustion environments is unknown. In this study, CrNbO4 and CrTaO4 were exposed to high velocity steam for times up to 96h at temperatures of 1300°C and 1500°C, respectively. Mass change, material recession, and compositional change were monitored. It was found that both materials exhibited mass loss and measurable recession rates under these test conditions. Refractory alloys forming these oxides would require environmental barrier top coats to be used successfully for hot section turbine engine components. |