MECHANICAL BEHAVIOURS OF UNIDIRECTIONALLY SOLIDIFIED OXIDE MATERIALS

Most conventional ceramics and ceramic composites are produced by using the powder sintering method. For this reason they contain many impurities and there are many cases of amorphous phases forming at grain boundaries. In many cases these amorphous phases and grain boundaries effectively act to increase fracture toughness and strength at room temperature but there are microstructural factors which might cause a deleterious effect on high temperature strength and creep proporties. The oxide ceramic single crystal materials eliminates these microstructural factors by controlling its stable high temperature microstructure. In this paper the microstructural and high temperature behaviours such as the flexural strength, thermal stability and creep characteristics of single crystal oxide materials are examined.