Sintering and vitrification heat treatment of cBN grinding wheels

Vitrification heat treatment of grinding wheels has been studied with great interest over the past 10 years but with very little work published in the area of superabrasive grinding wheels that use cubic boron nitride (cBN) and diamond as the abrasive medium. It has been shown that heat treatment of vitrified bonding systems has a remarkable effect on the resulting wear of the grinding wheel, which is shown by wide variations in the wheel wear parameter, grinding ratio. However, grinding wheels that contain cBN and diamond require bonding systems that fuse together under lower forming pressures and vitrification temperatures. This paper describes the initial stages of powder selection, consolidation and vitrification heat treatments applied to these types of grinding wheels, and shows that using bonding materials that contain very low quartz content can decrease the tendency for the grinding wheel to wear out very quickly.