MOCVD of alumina-silica oxidation resistant coatings on carbon fibers Original Research Article

Carbon (graphite) fibers have been coated with amorphous alumina-silica (Al2O3)x (SiO2)y thin films by metal organic chemical vapor deposition (MOCVD) using [Al(OSiEt3)3]2 as a single-source precursor. The adhesion of the alumina-silica films to the carbon fibers and/or the filmsʹ flexibility is a function of the residual carbon content in the film, as controlled by the carrier gas composition (ArO2). Aluminum matrix-carbon fiber composites have been prepared. While the alumina-silica thin film coatings successfully prevent both oxidation of the fiber and reaction between the fiber substrate and aluminum matrix, no wetting occurs. Use of an interfacial reaction in addition to the (Al2O3)x (SiO2)y film does lead to wetting and the formation of a stable composite.