Development of Functionally Gradient Material

This paper discribes the development of Functionally Gradient Material (FGM) which is promoted by Science and Technology Agency with "special coordination funds for promoting science and. technology" from 1987. FGM is an advanced metal/ceramic compositional gradient from a metal side to a ceramic side to obtain the function of the thermal stress reduction In the high temperatur circumstance such as aerodynamic heating or combustion chamber of space plane. The aim of the development Is completion of FGM with the function to withstand 2000 K In the ceramic side and the difference of 1000 K between both sides. which are generated by the high temperature gas and the active cooling system. The small-sized FGM with a diameter of 30 mm and a thickness of 1-10 mm is scheduled to be completed by March, 1990 and the large-sized FGM of 300 mm by 300 mm with 1-10 mm in thickness by March. 1992. The development is shared by three research groups such as material designing, fabrication and evaluation, which consist of 30 research Institutes including national institues, universities and private companies. Material design group developed expert system. Fabrication group produced small FGM test pieces by physical-chemical combination vapor deposition process, thin sheet lamination method, low pressure plasma spray method and self-propagating high temperature synthesis process. Evaluation group developed various techniques for thermal barrier performance, thermal fatigue properties, thermal shock resistance and etc.