Microstructure and thermal shock property of liquid phase sintered Cf/SiC composites

This paper dealt with a liquid phase sintering process for the fabrication of carbon fiber reinforced SiC matrix composites (Cf/SiC), using a ultra-fine SiC particles and oxide additive materials. Especially, the thermal shock properties of Cf/SiC composites were investigated at the elevated temperatures. The characterization of monolithic SiC materials by the variation of starting SiC particle size was also examined. Monolithic SiC materials possessed an excellent density higher than about 3.0 mg/m3 and a good flexural strength of about 700 MPa, regardless of starting SiC particle size. Cf/SiC composites also represented a dense morphology in the intra-fiber bundle region, even if there were some amount of pores. However, the flexural strength of Cf/SiC composites greatly decreased at the thermal shock temperature of 400 °C.