FABRICATION OF THIN OXIDE COATINGS ON CERAMIC FIBERS BY A SOL-GEL TECHNIQUE

Various metal oxides are potential reaction barriers in titanium/silic on carbide composites. A sol-gel process utilizing metal alkoxides was developed to coat silicon carbide fibres with relatively thick, crack -free, adherent layers of yttrium and calcium oxide. A multiple-dip te chnique was employed in order to avoid cracking due to large residual thermal and drying stresses produced in the film. The influence of sev eral processing parameters and the geometry of the substrate on the co ating thickness is discussed.