LASER-ABLATED COATINGS ON CERAMIC FIBERS FOR CERAMIC-MATRIX COMPOSITES

The newly developed pulsed excimer laser ablation (PELA) thin film coa ting technique was applied to coating ceramic fibers for ceramic matri x composite applications. The feasibility of this application was demo nstrated in the coating of two of the most popular monofilaments, SiC (SCS-0) and sapphire. Several materials, such as graphite, SiC and ens tatite (MgSiO3) were used as coating targets. Single-layer or multiple -layer coatings of these materials were deposited on either SiC or sap phire filaments. The microstructure, stoichiometry and thickness of th e coatings were examined using scanning electron microscopy, energy-di spersive spectroscopy and Auger electron spectroscopy. The coatings ex hibited a dense and uniform morphology, and the stoichiometry compared well with the targets throughout the coating layer. Although the coat ing was applied discontinuously on cut filaments, the potential applic ation of the PELA technique for continuous fiber coating has been demo nstrated.