ABSTRACT
Ceramic materials in general have very attractive properties such as high hardness and modulus, strength retention at high temperatures, chemical inertness, and low density. Even then these materials are not very popular as metallic materials for engineering applications, mainly because of their low toughness. This type of brittle materials is prone to catastrophic failures. They are also extremely susceptible to thermal shock though they can withstand high temperatures. Most of the ceramic components are exposed to thermal cycles during fabrication/service, and this may introduce defects in them because of the poor thermal shock resistance. Unlike polymer and metal matrix composites (PMCs and MMCs), the main consideration in developing a ceramic matrix composite (CMC) is to increase the toughness. Hence, for most CMCs, the driving force to form composites is to enhance the mechanical reliability of inherently brittle ceramic materials, while retaining their attractive properties.
