ELASTIC ANISOTROPY OF CARBON-CARBON COMPOSITES DURING THE FABRICATION PROCESSES.

The elastic coefficients of carbon-carbon composites were measured at four steps during the fabrication process. An ultrasonic materials characterization testbed was ued to show that the carbonization-induced porosity drastically affects the anisotropy factor. These and other results suggest that the use of ultrasonic waves (by noncontact methods such as photoacoustics) could provide a meaningful technique for monitoring the fabrication process and thereby allow optimization of the control parameters and ultimately the quality and processing speed of the final product.