Tool wear control in single-crystal diamond cutting of steel by using the ultra-intermittent cutting method

Excessive tool wear is a major drawback to the ultraprecision cutting of steel with geometrically defined single-crystal diamond tools. This paper presents a new approach to reduce this wear. In general, the wear of the diamond tool is due to chemical reactions such as diffusion into the steel, oxidation, graphitization, and carbide formation under cutting conditions of high temperature and high pressure. To suppress these types of chemical reactions, the contact time between the diamond tool and the steel in the cutting process was controlled by intermittent cutting method such as fly-cutting or milling. A series of intermittent cutting experiments were carried out to control the tool–workpiece contact time in one cutting cycle by changing the cutting speed and cutting length in each cutting cycle. The experimental results showed that the diamond tool wear was highly dependent on the tool–workpiece contact time, regardless of the cutting speed, and that the wear was greatly reduced by decreasing the contact time to less than 0.3 ms under these cutting conditions. It is expected that steel can be successfully cut with a single-crystal diamond tool by controlling the tool–workpiece contact time.