Zrb2-Sic Composites' Surface Temperature Response To Dissociated Oxygen At 1600 Degrees C

The surface temperature response of ZrB(2-)30 vol% SiC composites exposed to dissociated oxygen was investigated using a side-arm oxidation facility. As the specimen was immersed in dissociated oxygen at 1600 degrees C, a sudden and spontaneous temperature jump accompanied by high degradation of composites was observed in the initial testing stage. For comparison, the surface temperature of pre-oxidized specimen was relatively low and maintained steady under the same testing conditions. The ZrB2-SiC composites' surface temperature response to dissociated oxygen could be linked to the competition between oxidation and catalytic reactions, and the temperature jump of the original specimen was mainly ascribed to the oxidation of composites with atomic oxygen. Pre-oxidation of ZrB2-SiC composites in static air could effectively inhibit the surface temperature jump phenomenon of composites under simulated service conditions. (C) 2016 Elsevier Ltd and Techna Group S.r.l. All rights reserved.