Silicon based substrate with environmental/ thermal barrier layer
AssigneesGeneral Electric Company, United Technologies Corporation, The United States of America as represented by the Administrator of the National Aeronautics and Space Administration
InventorsHarry Edwin Eaton, Jr., William Patrick Allen, Nathan S. Jacobson, Nanottam P. Bansal, Elizabeth J. Opila, James L. Smialek, Kang N. Lee, Irene T. Spitsberg, Hongyu Wang, Peter Joel Meschter, Krishan Lal Luthra
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Abstract
A barrier layer for a silicon containing substrate which inhibits the formation of gaseous species of silicon when exposed to a high temperature aqueous environment comprises a barium-strontium alumino silicate.
Claims53
An article comprising:
- a substrate comprising silicon;
- and
- a gaseous species of Si formation inhibiting barrier layer, wherein the barrier layer is selected from the group consisting of (a) barium oxide, (b) barium aluminosilicate, (c) barium strontium aluminosilicate, (d) from about 0.00 to 1.00 moles BaO, from about 0.00 to 1.00 mole SrO, about 1.0 mole Al2O3 and about 2.00 mole SiO2 wherein the total of BaO and SrO is about 1.00 mole and (e) from about 0.00 to 1.00 mole BaO, from about 0.00 to 1.00 mole of an oxide of a second alkaline earth metal, about 1.00 mole Al2O3 and about 2.00 mole SiO2, wherein BaO plus the other alkaline earth metal oxide total 1 mole wherein the barrier layer has a crystallographic structure which is at least 50% by volume celsian and inhibits the formation of a gaseous species of Si when the article is exposed to a high temperature, aqueous environment.
An article according to claim 12 wherein the barrier layer comprises from about 0.25 mole to about 0.75 mole BaO and from about 0.25 mole to about 0.75 mole of a second alkaline earth oxide.
An article comprising:
- a substrate comprising silicon;
- a gaseous species of Si formation inhibiting barrier layer, wherein the barrier layer inhibits the formation of a gaseous species of Si when the article is exposed to a high temperature, aqueous environment;
- and
- an intermediate layer between the substrate and the barrier layer wherein the intermediate layer is selected from the group consisting of SiO2, mullite, mullite-barium strontium aluminosilicate, mullite-yttrium silicate, mullite-calcium aluminosilicate, barium strontium aluminosilicate, calcium aluminosilicate, and silicon metal.
An article comprising:
- a substrate comprising silicon;
- and
- a gaseous species of Si formation inhibiting barrier layer, wherein the barrier layer consists essentially of BaO up to 1.00 mole, from about 0.00 to 1.00 mole of an oxide of a second alkaline earth metal, about 1.00 mole Al2O3 and about 2.00 mole SiO2, wherein BaO plus the other alkaline earth metal oxide total 1 mole inhibits the formation of a gaseous species of Si when the article is exposed to a high temperature, aqueous environment.
Dependencies are inferred from the claim text.