Abstract
Polishing is widely used in the finishing process of hard and brittle materials. This is because the surfaces finished by polishing don't contain damage, and their degree of roughness is less than that of other processes. However, polishing has some disadvantages ; for example, low efficiency and also the effect that the waste material which is generated may have on the environment. Conversely, a grinding process has the following advantages ; it is highly efficient, more environmentally friendly and various shapes can easily be obtained. However, the surface quality is worse than that of polishing. Therefore, if a new mirror-grinding wheel can be developed, we will be able to obtain a smooth ground surface as good as polishing. Historically, people have used some specific natural stones as grinding tools. Some of them outperform artificial grinding tools in the finishing process. In this paper, the fundamental characteristics of natural whetstones will be examined. It was found that their structure was composed of layers. Also, a new grinding wheel has been developed. It has a layered structure, and flake graphite was used for the layers. The capability of the newly developed grinding stone was measured by performing a dry grinding test. The work material was a silicon wafer. The ground surface roughness, Ra, was improved from 14nm to 3nm. This grinding stone could be used for mirror grinding.
