Recent trends in the development of fine ceramics in Japan

Abstract

In Japan, the 10 year programme initiated by the Ministry of International Trade and Industry (MITI) on the fine ceramics research and development project has been in progress since 1981. In the first phase of the project, bench-scale tests on the preparation of fine powders of Si 3N 4 and SiC, and the forming and sintering of commercial powders on a test piece scale, were carried out. It is believed that the objectives in this phase have almost been accomplished successfully. In the second phase, work on larger-scale powder preparation, on processing full-sized samples of simple shape, on cutting and grinding, on property measurements, on non-destructive evaluation and on other tasks are ongoing. In addition to the MITI programme, many other research and development programmes are being conducted in Japan. The interesting results and the present status of these are reported. Research and development programmes are being conducted to modify the processing, to improve properties, to increase reliability in strength and to reduce production cost. These topics include improved injection moulding and ultrahigh pressure cold isostatic pressing. Special efforts have been made to increase the Weibull modulus and fracture toughness of these products and also to reveal relationships between these properties and the microstructure. Finally, the applications of fine ceramics in Japan are described in Appendix A.