High temperature ceramic filter

摘要

A porous refractory product suitable for use in filtering high temperature combustion products. The product includes a matrix of recrystallized silicon carbide formed by heating a cast preform containing relatively coarse silicon carbide crystals selected to produce the desired permeability, and relatively fine silicon carbide crystals to a temperature of at least 2320° C. At this temperature, the relatively fine silicon carbide crystals sublime and condense on the relatively large crystals. This results in recrystallization of the cast preform to form the porous matrix with the desired permeability.