To grind the modern ceramics at high material removal rate, it, is very important to understand the grindability. In this study, a series of alumina ceramics with several grain sizes was ground at constant pressure using diamond grinding wheel. The specific grinding energy which was calculated from a material removal rate and a tangential grinding force was adopted as a criterion of grindability. Conclusions obtained are : (1) The grindability of hipped alumina ceramics can be estimated from both grain size and MOR value. (2) Both brittle fracture and plastic deformation are responsible for the chip generation in grinding of fine-grain alumina ceramics, but the brittle fracture became dominant for coarser-grain material.
