Methods of inhibiting catalyzed oxidation of carbon-carbon composites using phosphoric acid, a zinc salt, and an aluminum salt and articles made therefrom

Abstract

This invention relates to a method of inhibiting catalyzed oxidation of carbon-carbon composites involving the steps of treating a carbon-carbon composite having pores with a liquid composition, preferably an aqueous solution, containing (a) phosphoric acid, (b) a zinc salt, and (c) an aluminum salt and heating the treated carbon-carbon composite to a temperature sufficient to form deposits within the pores. In one aspect, the deposit comprises a dispersion of aluminum-rich phosphate in zinc-rich phosphate. This solution may be used in combination with a silicon carbide barrier coating, applied by either painting or by CVD, to allow application at higher temperatures. The adherence of the barrier coating may be improved by preoxidizing the surface to increase porosity at the surface. Articles, including friction brakes, and the aqueous compositions are also part of this invention. The methods and articles show improved penetration and retention of the catalyzed oxidation inhibitors.

Dependencies are inferred from the claim text.