A research team led by Kazuya Yamamura, an associate professor of Osaka University, developed a polishing technology to smooth the surface of such hard materials as silicon carbide without damaging it. The technology is to polish the surface using an abrasive grain softer than the base material, while irradiating the surface with plasma to make it soft. It uses cerium oxide abrasive grain used to polish glass that is softer than silicon carbide, while oxidizing the surface using atmospheric-pressure plasma made up of vapor and helium gas.
It takes only about one hour for the newly developed plasma-aided polishing method to smooth the surface of off-the-shelf silicon carbide. Improvement of the efficient use of plasma oxidation can shorten the time. Because it uses glow discharge plasma processable at a low temperature, the surface temperature is lower than 100 degrees centigrade and not affected by temperature rise. In addition, it is eco-friendly because it does not use chemicals and because it is free from any cost to treat the chemicals. It can be applied to the polishing of such ultrahard materials as sapphire substrate, tungsten carbide, and sintered silicon carbide. The research team plans to put the new technology into practical use in alliance with companies.