Surface Enhancement of Silicon Carbide Filament for Metal Matrix Composites.

Abstract : The first year's efforts on this program were aimed at understanding the mechanisms of strengthening and degradation of SiC filament. Filaments were provided for analysis here in part by Avco IRAD and other related programs listed at the end of this report. The specific objectives were: (1) Devise a model for filament strengthening/degradation effects due to the presence of surface layer's or coatings on a brittle ceramic filament; (2) Determine properties of the carbon rich layer and propose mechanisms for filament strengthening; and (3) Utilizing the above model and mechanisms, analyze alternative surfaces that can potentially provide surface strengthening, resist strength degradation in molten Al, and bond with Al alloys during casting, hot molding or diffusion bonding operations.