NONDESTRUCTIVE EVALUATION FOR LARGE-SCALE METAL-MATRIX COMPOSITE BILLET PROCESSING

Nondestructive evaluation (NDE) has been conducted on a large-scale, silicon carbide particulate (SiC(p))-reinforced metal matrix composite (MMC) billet. Using powder metallurgy techniques, a 335-mm long x 349-mm diameter MMC billet was specially fabricated to contain implanted discontinuities, such as clusters of SiC(p) and aluminum powders, and was utilized for nondestructive characterization. Ultrasonic techniques were capable of identifying SiC(p) clusters in the billet, while eddy current methods could be used to determine near-surface density variation in the billets. Multiple NDE techniques could be employed to evaluate microstructural characteristics of composite billets. These results indicate that NDE techniques can be integrated into manufacturing processes to provide on-line, process-interactive control of fabrication parameters.