A process for increasing the thermal stability of silicon carbide

摘要

The thermal stability of silicon carbide is increased by treatment with a solution of phosphoric acid or a solution of a water-soluble phosphate. The silicon carbide may be in the form of crystals, powder, granular particles or sintered material. In an Example silicon carbide heating elements were heated at 130 DEG C. for 2 hours in an 85% solution of phosphoric acid, washed, dried at 110 DEG C. and calcined. The treated silicon carbide may be mixed with 1 to 10% of silica, water glass and tar, moulded, dried and calcined at 1900 DEG C.