Ultrasonic spectroscopy together with optical microscopy were used to study the distribution of porosity in two-dimensional carbon-carbon composites. In the frequency-dependent (0. 5-3. 0 MHz) attenuation, characteristic features are found which lead to separate estimates of mean size and volume fraction of pores. Four samples of two-dimensional carbon-carbon composites were studied, corresponding to each of four key steps in the fabrication process. A method was developed to analyze the data. A correlation between the degree of porosity and ultrasonic attenuation was found in qualitative agreement with theory. The absence of quantitative agreement is thought to be a result of nonideal (nonspherical) geometry of the pores.
|Original language||English (US)|
|Number of pages||4|
|Journal||Ultrasonics Symposium Proceedings|
|State||Published - Dec 1 1986|
All Science Journal Classification (ASJC) codes