PROTECTIVE COATING FOR POROUS REFRACTORIES

摘要

A porous refractory object, more particularly a porous silicon carbide igniter is shown, the interconnecting pores and passageways of its body being filled with sub-micron sized silicon carbide particles deposited therein from a slurry coated on the surface of the object, which particles are subsequently oxidized at least on the surface and within the passages or pores in the subjacent surface portion of the body, to provide a protective coating of silica within the pores and on the surfaces of the object to preclude oxidation of the internal phases of the body of the object in oxidizing atmospheres.