Reinforcement of ceramic matrix composites by ceramic continuous fibers

Ceramics need to be reinforced because of their inherent brittleness and lack of reliability. Only continuous fibers are able to arrest the cracks through deflection at fiber/matrix interfaces. Only those fibers that can withstand the high temperatures required by composite processing (> 1000°C) without significant damage can be used. This chapter focuses on continuous reinforcement of ceramics by ceramic fibers: SiC, carbon or oxide fibers that are capable of withstanding high temperatures (to about 2500°C for carbon fibers). Features of the mechanical properties and the mechanical behavior of single filaments and multifilament tows at room and elevated temperatures are discussed. The influence of fibers on composite mechanical behavior and properties, is also considered. The influence of fiber reinforcement on composite damage tolerance, fracture toughness, and reliability is shown to be dependent on fiber/matrix interface/interphase characteristics.