High temperature low thermal expansion ceramic
First Claim
1. A sintered ceramic article containing iron-aluminum titanate solid solution and mullite as the predominant crystal phases with a minor amount of a rare earth metal oxide crystal phases, said article exhibiting grain boundary and intracrystalline microcracking and consisting essentially, expressed in terms of weight percent on the oxide basis, of 1.5-20% SiO2, 225-25% Fe2 O3, 35-75% Al2 O3, 10-40% TiO2, and 0.1-5% RE2 O3.
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Abstract
This invention relates to the high temperature stabilization of aluminum titanate and aluminum titanate-mullite compositions by the addition of iron oxide. It has been found that iron oxide concentrations greater than 5 weight percent and as high as approximately 25 weight percent have a stabilization effect at high temperatures on aluminum titanates. The resultant ceramic body is further enhanced by the addition of from 0.1 to 5 weight percent rare earth oxide.
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12 Claims
- 1. A sintered ceramic article containing iron-aluminum titanate solid solution and mullite as the predominant crystal phases with a minor amount of a rare earth metal oxide crystal phases, said article exhibiting grain boundary and intracrystalline microcracking and consisting essentially, expressed in terms of weight percent on the oxide basis, of 1.5-20% SiO2, 225-25% Fe2 O3, 35-75% Al2 O3, 10-40% TiO2, and 0.1-5% RE2 O3.
- 10. A sintered ceramic body consisting essentially of, by weight percent, 50 to 75 percent iron-aluminum titanate solid solution, 20 to 50 percent mullite, and 0.1 to 5 percent rate earth oxide.
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