Multiparameter Ultrasonic Evaluation of Ceramic Matrix Composites
Quantitative multiparameter ultrasonic methods are under development for the evaluation of composite materials. Dual frequency, throughtransmission, tone burst signals are used to provide calibrated attenuation data and the frequency dependence thereof. Pulse-echo, spike pulse signals are used to obtain depth information for internal reflectors. Monostatic and bistatic backscatter and bistatic forwardscatter techniques are also used to increase sensitivity to small flaws. Example results are presented for silicon carbide (SiC) fiber reinforced lithium alumino silicate (LAS) glass-ceramic matrix composites. Results include those for manufactured and naturally occurring flaws.