Preparation and Characterization of SiO2/SiCp Composite

SiO2 was coated on SiCp by a sol-gel method. The deterrent factors, such as the amount of H2O and the pH value, were analyzed for their effect on the hydrolysis rate. SiCp-SiO2 composites were prepared by conventional sintering. The heterogeneous-deposition and the sot-gel method was the optimum way to achieve coated SiCp-SiO2 composite particles. XRD, SEM and DTA-TG techniques were employed to characterize the composites. SiCp and SiO2 dispersed homogeneously within the composite powders. Excess water was proven to accelerate the hydrolysis rate of TEOS. A two step sot-gel method, initially with acid catalyst and subsequently with alkali one, was an effective way to reduce the reaction time. The optimized sintering temperature was 1500 degrees C.