Continuous fiber reinforced ceramic matrix composites

Abstract Ceramic matrix composites (CMCs) have been developed to overcome the intrinsic brittleness and lack of reliability of monolithic ceramics. The main objective was to introduce ceramics in structural parts used in severe environments, such as in rocket engines and heat shields for space vehicles. Replacing heavy super alloys with CMCs in advanced engines will allow an increase of the temperature at which the engine can be operated and will yield significant weight saving. The present chapter deals with the state of the art on the material design, processing, properties control and applications of fiber reinforced Ceramic Matrix Composites during the last few years. The chapter starts with a discussion on the current state-of-the-art reinforcement materials used for the fabrication of continuous fiber reinforced ceramic matrix composites. The discussion also focuses on the different types of fiber architectures currently being used/developed. The fiber/matrix interfacial domain is a decisive constituent of continuous fiber reinforced SiC based Ceramic Matrix Composites. Here the fiber/matrix interfacial characteristics are examined with respect to crack deflection and composite mechanical behavior. An account of the processing routes of CMCs, focusing PIP processing using various preceramic polymers is provided. An appreciation on the ability of this route in controlling the microstructure and elemental composition and its effect in controlling the final thermo-mechanical properties of the matrix is included. Final section of the chapter deals with the oxidation behavior of Ceramic Matrix Composites, need for oxidation protection coatings, requirements for a good coating material, various research activities carried out on oxidation protection coatings, different methods of applying the coating and finally future scope of developing coatings for ultra-high temperature environments.