An investigation of grinding with electroplated CBN wheels

Grinding of hardened bearing steel with electroplated CBN wheels was investigated with particular attention to how the wear of the abrasive grains affects the wheel topography and grinding performance during the wheel life. Power, surface roughness, and wheel topography data were obtained throughout the wheel life for internal cylindrical grinding. Dulling of CBN grains by attrition was found to cause an increase in the grinding power, but the degree of dulling was restricted mainly by grain fracture and also by grain pullout. Grain fracture and pullout had a much smaller effect on the progressive increase in active grain density, which caused the surface roughness to progressively decrease. Wheel failure tended to occur by stripping of the abrasive layer when the radial wear reached about 70%-80% of the grain dimension.