Studies on refractory bonding systems used in vitrified silicon carbide grinding wheels

Abstract

The performance of vitrified silicon carbide grinding wheels is dependent on the molten properties of their bonding systems. The erosion of silicon carbide during the manufacture of grinding wheels is enhanced by the action of high glass content vitrified bonding systems that reduces their wear resistance during the grinding process. Replacing the glass content of the bond with a clay that does not vitrify can improve their wear resistance. However, the harmful effects of quartz particles that are found in clay minerals need to be eliminated during the firing process before the grinding wheels are used to grind precision engineering components. A mathematical model describing the dissolution of quartz in refractory bonding systems was compared with experimental data using X-ray diffraction techniques. It was found that when grinding wheels were isothermally heat treated, the residual mass fraction of quartz was found to be a function of time. When compared with experimental data, the model was found to be accurate for short periods of heat treatment that are associated with vitrified silicon carbide firing cycles. The model is of practical use for predicting the complete dissolution of quartz in vitrified bonding systems used for high-performance silicon carbide grinding wheels.