ABSTRACT
Functionally Graded Materials (FGM), which are initially proposed by group of Japanese aerospace researchers, are composite materials formed of two or more constituent phases in which material properties vary smoothly from one surface to the other (Koizumi 1997). Consequently, FGMs are able to avoid high interlaminar shear stresses, stress concentration and delamination phenomenon which are often cited as the drawbacks of laminated composite materials. The common FGMs are usually composed of the mixture of ceramics and metals due to the better thermal resistance of ceramic phase and the stronger mechanical performance of metal phase. Owing to these striking advantages, the FGMs are extensively used in many scientific and engineering fields, such as electronics, optics, chemistry, biomedical engineering, nuclear engineering (Birman and Byrd 2007).
