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, Narottam 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.
Claims28
A method for preparing an article comprising the steps of:
- providing a substrate comprising silicon;
- and
- applying a gaseous species of Si inhibiting barrier layer to the substrate wherein the barrier layer has a crystallographic structure which is at least 5.0% by volume celsian and inhibits the formation of a gaseous species of Si when the article is exposed to a high temperature, aqueous environment and wherein the coefficient of thermal expansion of the barrier layer is within ±3.0 ppm/° C. the coefficient of thermal expansion of the substrate.
A method for preparing an article comprising the steps of:
- providing a substrate comprising silicon;
- grit blasting the substrate with particles having a particle size ≦30 microns and applying a gaseous species of Si inhibiting barrier layer to the substrate wherein the barrier layer inhibits the formation of a gaseous species of Si when the article is exposed to a high temperature, aqueous environment.
A method for preparing an article comprising the steps of:
- providing a substrate comprising silicon;
- oxidizing the substrate to form a layer of SiO2;
- applying a gaseous species of Si inhibiting barrier layer to the oxidized substrate wherein the barrier layer inhibits the formation of gaseous species of Si when the article is exposed to a high temperature, aqueous environment.
A method for preparing an article comprising the steps of:
- providing a substrate comprising silicon;
- applying a gaseous species of Si inhibiting barrier layer to the substrate wherein the barrier layer inhibits the formation of gaseous species of Si when the article is exposed to a high temperature, aqueous environment;
- and
- heat treating the article at a temperature of about 1250° C. for about 24 hours.
A method for preparing an article comprising the steps of:
- providing a substrate comprising silicon;
- and
- applying a gaseous species of Si inhibiting barrier layer to the substrate wherein the barrier layer has a crystallographic structure which is at least 5.0% by volume celsian and consists essentially of 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 and inhibits the formation of gaseous species of Si when the article is exposed to a high temperature, aqueous environment.
A method for preparing an article comprising the steps of:
- providing a substrate comprising silicon;
- and
- applying a gaseous species of Si inhibiting barrier layer to the substrate wherein the barrier layer is selected from the group consisting of (a) barium aluminosilicate, (b) barium strontium aluminosilicate, (c) 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 (d) 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.
Dependencies are inferred from the claim text.