High temperature stabilized mullite-aluminum titanate
AssigneeCorning Incorporated
InventorDavid L. Hickman
Life of this patent
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Abstract
This invention relates to a sintered mullite-aluminum titanate article formed by doping the mullite with 1-5% titania and/or titania precursors, and 1-5% hematite and/or hematite precursors, pre-calcining the mullite and mixing with calcined aluminum titanate to form a mullite-aluminum titanate composition which may be formed into a high temperature stabilized ceramic article such as a honeycomb.
Claims9
A method of producing a high temperature stabilized mullite-aluminum-titanate article, the article consisting essentially, expressed in weight percent based on the oxides, of 1.5-20%, SiO.sub.2, 5-25% Fe.sub.2 O.sub.3, 35-75% Al.sub.2 O.sub.3, and 10-40% TiO.sub.2, said method comprising the steps of:
- forming doped mullite by a process selected from:
- (1) doping mullite with dopant selected from titania, titania precursors, hematite, and hematite precursors to form doped mullite;
- and (2) pre-reacting mullite precursors with dopant selected from titania, titania precursors, hematite, and hematite precursors to form doped mullite precursors;
- calcining and milling the doped mullite;
- calcining and milling aluminum-titanate;
- mixing the mullite and the aluminum-titanate with a binder to form a ceramic batch;
- shaping the ceramic batch to form a green ceramic article;
- and
- firing the green ceramic article at a temperature and for a duration of time sufficient to form the sintered ceramic article.
A method of producing a sintered ceramic body consisting essentially of the composition expressed in terms of weight percent based on the oxides, of 1.5-20% SiO.sub.2, >5-25% Fe.sub.2 O.sub.3, 35-75% Al.sub.2 O.sub.3. 10-40% TiO.sub.2, and 0.1-5% RE.sub.2 O.sub.3, the steps comprising:
- (a) calcining a mixture of Fe.sub.2 O.sub.3, TiO.sub.2 and Al.sub.2 O.sub.3 to a single phase solid solution;
- (b) grinding the solid solution to a powder;
- (c) mixing mullite with the powder to from a homogeneous body;
- (d) combining rare earth metal oxides either to the mixture prior to the calcining step or to the powder in the mixing step;
- and
- (e) firing the body to form the sintered ceramic body;
- the improvement being that prior to mixing the mullite with the powder to form a homogeneous body, the mullite is first (1) doped with dopant selected from titania, titania precursors, hematite, and hematite precursors to form doped mullite precursors, and (2) calcined.
A method of producing a sintered ceramic body consisting essentially of the composition expressed in terms of weight percent based on the oxides, of 1.5-20% SiO.sub.2, 5-25% Fe.sub.2 O.sub.3, 35-75% Al.sub.2 O.sub.3, and 10-40% TiO.sub.2, the steps comprising:
- (a) calcining a mixture of TiO.sub.2 and Al.sub.2 O.sub.3 to a single phase solid solution;
- (b) grinding the solid solution to a powder;
- (c) doping mullite with hematite;
- (d) calcining the doped mullite;
- (e) mixing the doped mullite with the powder to form a homogeneous body;
- and
- (f) firing the body to form the sintered ceramic body.
Dependencies are inferred from the claim text.