The sound impedance of C/ SiC composite is measured by the method of ultrasonic immersing pulse echo,and which is between 4. 0×10 6 kg/ m 2 s and 4. 7×10 6 kg/ m 2 s. The relationship of reflection is about 1 when there is crack in brazing interface and it is between 0. 71 and 0. 74 when there is no crack. For the differential value of the amplitude of reflection wave is at least 6 dB between two status, the amplitude of more than second reflection wave will be monitored when C-scan. The result of C-scan is certified by metallographic analysis, and the uniformity of both is good. |