FGM activities in Japan

The concept of functionally graded materials (FGMs) was proposed in 1984 by materials scientists in the Sendai area as a means of preparing thermal barrier materials. Continuous changes in the composition, microstructure, porosity, etc. of these materials results in gradients in such properties as mechanical strength and thermal conductivity. In 1987, a national project was initiated entitled 'Research on the Basic Technology for the Development of Functionally Gradient Materials for Relaxation of Thermal Stress'. In 1992 when the project was finished, samples of 300 mm square shell and 50 mm diameter hemispherical bowls for SiC-C FGM nose cones were prepared. The concept of FGMs is of interest not only in the practical design of super refractory materials, but also in the development of various functional materials. In 1993, the second national project was initiated for the research and development of FGMs as functional materials; 'Research on Energy Conversion Materials with Functionally Gradient Structure'. This program aims to apply functionally graded structure technology to the improvement of energy conversion efficiency. The project will continue until the fiscal year 1997. (C) 1997 Elsevier Science Limited. All rights reserved.