Al_2O_3和Y_2O_3包覆的SiC复合粒子制备

Preparation of Al_2O_3 and Y_2O_3-coated SiC Composite Particles

本文利用非均匀成核法，将Al（OH）3和Y（OH）3均匀地包匿在SiC粒子表面，制备出被覆Al2O3和Y2O3的SiC复合粒子．包覆Al（OH）3的SiC粒子，其等电点IEP的pH=3．4移至pH=7.3，再用Y（OH）3包覆表面被覆Al（OH）3的SiC复合粒子后，其等电点IEP又从pH=73移至pH=8.6左右．并且表面包覆的SiC粒子，其水悬浮液流变性质发生了变化．经盐酸滴定表明，涂层物质的包覆率可达95％以上．

Al2O3and 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.