Preparation of Al2O3 and Y2O3-coated SiC composite particles

Al2O3 and Y2O3-coated SiC composite particles were prepared from SiC coated uniformly with Al(OH)(3) and Y(OH)(3) by heterogeneous nucleation process. The IEP of as-received SiC is pH 3.4, that of Al(OH)(3)-coated SiC shift to pH 7.3. When Al(OH)(3)-coated SiC composite particles were coated with Y(OH)(3), its IEP is about pH 8.6. In addition, the viscosity behavior of SiC was changed via coating. The coating ratio is over 95% according to the results of hydrochloric acid titration, that is, 95% of added coating materials can be coated on the surfaces of SiC particles by heterogeneous nucleation process.