CVD of mono and double-layers on Si-B-N-C fibres

The reinforcement effects of the fibres in metal matrix composites (MMC) or ceramic matrix composites (CMC) are widely influenced by coatings acting a s diffusion barriers, sliding layers or protection against oxidation. Mono layers and double-layer systems was deposited by isothermal CVD process to newly developed ceramic fibres [1] of type of quarternary ceramic Si-B-N-C. The design of continuous multi-stage deposition process and the effect of chemical composition of deposited films will be discussed. Variations of la yer compositions were extensively investigated by SEM, TEM, SIMS, XPS and R aman spectroscopy. A great importance was attached to characterization of i nterfaces.