COATED CARBONACEOUS ARTICLES AND METHOD FOR MAKING SAME

Abstract

A method for producing a protective coating on the surface of a carbonaceous substrate is described. A substantially uniform coating of a liquid or solid precursor material is provided on the surface of the substrate. The precursor material is one which has boron-oxygen bonds and is substantially non-reactive with the substrate at a first relatively low temperature and is capable of reacting with the substrate at a second temperature which is substantially higher than the first temperature. The substrate is then raised to the second temperature to react the coating with the substrate to form a porous region of substantially uniform depth in the substrate surface. This region contains interconnecting interstices and boron carbide. The interconnecting interstices are then at least partially filled with a glass forming material such as boron, boron oxide, boron carbide, silicon, silicon alloy, silicon dioxide, silicon nitride, silicon oxynitride, germania, and mixtures thereof. A refractory coating may then be deposited on the filled layer. Also described is a coated article produced in accordance with the described method.

Source: Google Patents

35 USC §181 Secrecy Order

Inventor

• 1PAUL N. DYER