Crystallization of grain boundery phases in silicon carbide ceramics
AssigneeLanxide Technology Company, LP
InventorRoger Lee Ken Matsumoto
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Abstract
A silicon carbide ceramic having crystalline grain boundary phases is prepared by heating a composition comprising silicon carbide, a silicate glass and a high metal content transition metal silicide, to a temperature of 1300.degree. C. to 2100.degree. C. under vacuum until oxygen is removed from the glass as SiO gas, and the glass that remains within the silicon carbide ceramic crystallizes.
Claims20
An article comprising a sintered silicon carbide composition having grain boundary interfaces, comprising at least one material selected from the group consisting of beta-silicon carbide and alpha-silicon carbide, and further comprising CoSi, wherein said grain boundary interfaces within said article are substantially free of any glassy intergranular phase.
An article comprising a sintered silicon carbide composition having grain boundary interfaces, comprising at least one material selected from the group consisting of beta-silicon carbide and alpha-silicon carbide, and further comprising at least one high metal content silicide of a transition metal of IUPAC group 3, 4, 5, 6, 7, 8, 9, 10, or 11, wherein said grain boundary interfaces within said article are substantially free of any glassy intergranular phase.
An article comprising a sintered silicon carbide composition comprising a mixture, said mixture comprising:
- at least one material selected from the group consisting of beta-silicon carbide and alpha-silicon carbide;
- a high metal content silicide of a transition metal of IUPAC Group 3, 4, 5, 6, 7, 8, 9, 10 or 11;
- at least one carbide of said transition metal;
- and
- a devitrified glass comprising a polycrystalline decomposition reaction product of a silicate glass, said decomposition resulting from the evolution of silicon monoxide gas from said silicate glass.
Dependencies are inferred from the claim text.