Revealing thermal ablation mechanisms of C/SiC with in situ optical observation and numerical simulation

Abstract Structural ceramics such as C/SiC (carbon fiber reinforced silicon carbide) are of great importance for high temperature applications, where thermal ablation could occur and impair the structural integrity. Here we adopt in situ and real time optical visualization technique and numerical simulation to study the thermal ablation mechanisms on C/SiC subjected to oxyacetylene flame. The in situ optical setup captures the real time surface evolution at temperatures up to 1800℃, demonstrating clearly the formation of surface gas bubble, the flowing and merging process of liquid SiO2, which are later well reproduced and explained by the numerical simulation. Four different surface ablation regions on the sample subjected to thermal ablation have been identified by the captured images and flow field streamlines, which reveal the distribution and flow mechanism of SiO2 droplets on the C/SiC surface.