There has been a great deal of recent public interest in allergic reactions to the metals used for dental applications, and there is concern about biomedical use of metallic materials. Purity titanium has excellent biocompatibility, and shows reduced possibility of metal allergy. Due to the low thermal conductivity and high chemical reactivity, the machining of purity titanium is very difficult. Therefore, purity titanium is not widely used in dental materials. In this study, a polyurea resin-bonded mounted silicon carbide wheel was developed for polishing purity titanium. Using this mounted wheel, polishing of purity titanium was achieved over a short time compared with four commercially mounted wheels designed for use by dentists and dental technicians.

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SiC is a promising next-generation device application. In device fabrication, atomically smooth and damage-free SiC substrates are required for producing high-quality epitaxial films and gate-oxide interfaces. However, such SiC substrates are relatively difficult to machine because of its mechanical hardness and marked chemical inertness. Due to these factors, a method for polishing single-crystal SiC using ultraviolet irradiation (UV-polishing) was developed to obtain surfaces with a mirror finish. This paper describes determination of the optimum particles for UV-polishing. The results indicated that the optimum particles for polishing SiC are CeO₂. The surface roughness achieved was 0.12 nmRa.

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To evaluate the heat resistance of the field emission (FE) properties of nano-diamond/carbon nanowall (ND/CNW), we investigated the changes in FE and surface texture due to heating the samples in the atmosphere. Among the three samples heated at 450°C, 500°C, and 550°C in one hour, the samples heated at higher temperature had a lower threshold field, which induced an electron emission density of 1 mA/cm². When the heating time was increasing at a temperature of 550°C, it caused not only the reduction of the threshold field but also a decrease in thickness of the ND layer. Heating the samples at 600°C for one hour resulted in further a decrease in thickness of the ND layer and degradation of FE properties. By 3 hours heating at 600°C, most of the ND/CNW layers were burned off. The reductions of the threshold field of the sample by heating in the atmosphere were considered to be due to enhancement of the field at the tips of carbon sticks on the top of the ND layer, which was regarded as the emission sites and became thinner during thermal etching.

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