Nondestructive evalu[a]tion and mechanical behavior of continuous fiber reinforced ceramic matrix composites (CFCCs)

Monolithic ceramics are highly sensitive to processing-induced and/or servicerelated flaws, making them inherently brittle. Due to their low toughness, these materials fail catastrophically. However, continuous fiber reinforced ceramic matrix composites (CFCCs) can provide enhanced toughness as well as avoid catastrophic failure with some energy-dissipating mechanisms, such as crack deflection, debonding at the fiber-matrix interface, crack bridging, and fiber pullout, etc. In order to encourage wide applications of CFCCs, such as Nicalon(TM)/SiC, Nextel(TM)/Blackglas(TM), and Nicalon(TM)/CAS systems, nondestructive evaluation (NDE) of CFCCs is vital to characterize the integrity of the composites. Up to the present time, relatively little work has been performed on the NDE of CFCCs and on relating the NDE results to the understanding of mechanical behavior of CFCCs.