High-temperature strength of liquid-phase-sintered silicon carbide ceramics: A review

Silicon carbide (SiC) is a promising ceramic material for high-temperature structural applications, owing to its high flexural strength and room temperature (RT) strength retention ability at elevated temperatures (>= 1400 degrees C). This study reviews the influence of critical factors (grain-boundary structure, additive composition, additive content, microstructure, and testing atmosphere) on the RT strength retention at high temperatures and the high-temperature strength of LPS-SiC ceramics. The review suggests that (1) the minimization of additive content and careful selection of additive composition are crucial for achieving high flexural strength and excellent RT strength retention at >= 1500 degrees C, and (2) additive compositions without Al compounds exhibit great potential to achieve excellent RT strength retention at >= 1500 degrees C.