A method of protecting a carbonaceous article against oxidation and erosion at elevated temperature

摘要

A carbonaceous article, e.g., a carbon or graphite crucible or mold, is provided with an oxidation prohibitive coating comprising a rigid, glassy, ceramic, refractory material containing mullite and silicon carbide or boron carbide or both. The carbonaceous article has a coefficient of thermal expansion which is greater than about 1.5x10-6 inch/inch/ DEG C.