OXIDATION RESISTANT CARBON AND METHOD FOR MAKING SAME

Abstract

A coated carbon body having improved resistance to high temperature oxidation and a method for producing the coated carbon body are described. The coated carbon body comprises a carbon body, an intermediate glass forming coating and an outer refractory coating on the intermediate coating. The body has a converted porous layer formed by etching and reacting the body with boron oxide and the resulting converted layer contains interconnecting interstices and boron carbide formed by the reaction of the boron oxide and the carbon body. The method comprises contacting a carbon body with boron oxide at an elevated temperature sufficient to cause the reaction between the carbon body and boron oxide to form a converted porous layer which contains interconnecting interstices in the body and boron carbide and then applying the glass forming coating over the converted layer. Preferably an outer refractory coating is applied over the glass forming coating. The glass forming coating comprises compounds selected from the group consisting of silicon nitride, silicon oxynitride and mixtures thereof. Additionally, both the refractory outer coating and the glass forming coating can contain compounds selected from the group consisting of silicon nitride, silicon oxynitride, and mixtures thereof.

Source: Google Patents

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Inventor

• 1ROBERT A. HOLZL