Single-crystalline diamond or a sintered diamond cutting tools are used for precision processing and for difficult processing materials because diamond is the hardest known material. Nevertheless, natural and synthesized diamonds are so expensive that their industrial applications are limited. Diamond films can be synthesized inexpensively using chemical vapor deposition (CVD), but synthesized diamond film has a rugged surface and a dull cutting edge, causing severe problems when used as a cutting tool.
As described in this paper, the cutting edge of a diamond-coated cutting tool was reshaped to a sharpened form using electric discharge machining. To do so, the hot-filament CVD diamond film was made electrically conductive by doping with boron. The performance of this cutting tool was investigated using wood processing. Results show that the diamond-coated cutting tool prepared in this study was superior to a normal diamond-coated one in terms of cutting power consumption.