Ultraprecision Diamond Turning of Glass with Ultrasonic Vibration

Some brittle materials have found wide applications because of their excellent thermal, chemical, and wear resistance characteristics. Impeding the use of these brittle materials in precision engineering applications is the fact that currently it is very difficult for them to be machined in a way that ensures high precision in form and to a good surface finish. A non-traditional or unconventional machining technique incorporating ultrasonic technology [1] has been introduced to enable easier machining of otherwise hard-to-machine materials, and there exist various reports on ultrasonic abrasive machining and slurry drilling [2–4]. It is well known that the present machining technology using a diamond tool cannot be applied to steels because of excessive wear of the diamond cutting tool owing to high chemical activity of the carbon with the iron. However, Moriwaki and Shamoto [5] reported successful diamond-turning of stainless steel by applying ultrasonic vibration to the tool tip by which they obtained an optical quality mirror surface with an Rmax as low as 0.026 m and high-quality surfaces with a roughness less than Rmax 0.1 m and this could be done stably up to a