Oxidation resistant carbon containing alumina-silica articles

A shaped article comprising a continuous alumina-silica first phase, said first phase comprising 80 to 99 weight percent of the total composition of a mixture or chemical combination of 65 to 80 weight percent alumina and 20 to 35 weight percent silica, and an in-situ generated discontinuous carbon second phase, said carbon second phase comprising 1 to 20 weight percent of the total composition, and said article being stable to an oxidative atmosphere when heated at 1300.degree. C. for at least 30 minutes.

A shaped article comprising a continuous alumina-boria-silica first phase, an in situ generated discontinuous carbon second phase, and a mechanically added discontinuous silicon carbide third phase, said first phase comprising 65 to 84 percent of a mixture of 60 to 65 weight percent alumina, 25 to 35 weight percent silica, and 0.25 to 15 parts by weight boria, said second phase comprising 1 to 5 weight percent carbon, and said third phase comprising 5 to 30 weight percent silicon carbide, said article being stable to an oxidative atmosphere when heated at 1300.degree. C. for at least 2 hours.