The effects of SiO2 coating on diamond abrasives in sol-gel tool for SiC substrate polishing

摘要

In order to improve the dispersion and bonding force in the polishing tool, the diamond abrasives were surface modified by coating SiO2 layer through isothermal hydrolysis method in this study. Diamond abrasives with three different micro-nanoscale particle sizes were chosen to be modified. The structures and compositions of the modified diamond abrasives were characterized by transmission electron microscope (TEM) and Fourier transform infrared spectra (Hut). The results show that SiO2 thin film is uniformly grafted onto the diamond surface. The polishing films were prepared by using unmodified and modified diamond as abrasives based on Sol-Gel technology for the polishing tests of SiC substrates. The results of polishing tests show that the SiO2-modified diamond abrasives exhibit higher material removal rate (MRR) and better polishing quality than that of unmodified diamond abrasives. The improvement of polishing performance can be explained by the increment of dispersibility and the enhancement of binding force between the matrix of polishing film and abrasives after modification process.