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AssigneeGeneral Electric Company
InventorsBrian Hazel, Christine Walston, Irene Spitsberg
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A protective coating for use on a silicon-containing substrate, and deposition methods therefor. The coating has a strontium-aluminosilicate (SAS) composition that is less susceptible to degradation by volatilization and in corrosive environments as a result of having at least an outer surface region that consists essentially of one or more stoichiometric crystalline phases of SAS and is substantially free of a nonstoichiometric second crystalline phase of SAS that contains a substoichiometric amount of silica. The coating can be produced by carrying out deposition and heat treatment steps that result in the entire coating or just the outer surface region of the coating consisting essentially of the stoichiometric celsian phase.
A protective coating on a silicon-containing surface, the protective coating consisting essentially of strontia, alumina, and silica, and incidental impurities so as to have a strontium aluminosilicate composition, the protective coating having an outer surface region consisting essentially of one or more stoichiometric crystalline phases of strontium aluminosilicate and not more than 10 volume percent of a nonstoichiometric second crystalline phase of strontium aluminosilicate that contains a substoichiometric amount of silica.
A process of forming a protective coating on a silicon-containing surface, the process comprising a deposition and at least a first heat treatment step that result in the protective coating consisting essentially of strontia, alumina, and silica, and incidental impurities so as to have a strontium aluminosilicate composition, and having at least an outer surface region that consists essentially of one or more stoichiometric crystalline phases of strontium aluminosilicate and not more than 10 volume percent of a nonstoichiometric second crystalline phase of strontium aluminosilicate that contains a substoichiometric amount of silica.
Dependencies are inferred from the claim text.