SiC晶须表面涂覆Al_2O_3的溶胶-凝胶工艺及机理

SOL-GEL PROCESSES AND MECHANISM OF Al_2O_3 COATING ON THE SURFACE OF SiC WHISKER

用异丙醇铝为先驱体通过溶胶-凝胶工艺成功地在SiC晶须表面涂覆了5—30nm的Al_2O_2涂层。认为SiC表面与Al(OC_2H_7)_2(OH)形成配位键并构成胶团是形成涂层的重要机制。研究了溶胶浓度、晶须预处理,晶须直径和反复涂层对涂层效果的影响。

The Al_2O_3 coating of of 5—30nm thickness, measured by TEM and EDAX, on the surface of SiC whisker was successfully prepared by sol-gel processing using Al(OC_3H_7)_3 as a precursor. The influences of sol concentration, surface pretreating techniques and coating times on QV(volume of coating per unit volume of whisker)are investigated. It is suggested that covalent bond between SiC and Al_2O_3 on the interface and formation of colloidal group in SiC-Al(OC_2H_7)_2(OH)-CH_2OH-H_2O system are the important mechanism of coating.