Thermal response and oxidation behavior of Si-Ti-C-O fiber/Si-Ti-C-O ceramic matrix composites under atmospheric re-entry conditions

Abstract

National Aerospace Laboratory of Japan (NAL) has conducted a joint program to develop a continuous fiber reinforced ceramic matrix composite (CMC) for aerospace applications. The composite is referred to as NUSK-CMC from the initials of the collaborators, which exhibits excellent tensile strength and creep strength up to 1200°C in air. It has been attempted to apply NUSK-CMC to thermal protection system (TPS) of a future reusable space transportation system (space plane). For the purpose, thermal response and oxidation behavior under atmospheric re-entry condition were investigated using an arc jet facility. As a result, it was revealed that catalytic effect at the NUSK-CMC surface under plasma air stream was not significant. Furthermore, surface recession was hardly observed below 1450°C in surface temperature and above 5 kPa in oxygen partial pressure at the stagnation point, because passive oxidation was dominant under the heating condition. Passive-to-active oxidation transition of the composites agreed with the Balat's theory for silicon carbide under the present experimental condition.