Multilayer environmental barrier coating
AssigneeROLLS-ROYCE plc
InventorsStephanie Gong, Taylor K. Blair, Ngunjoh Lawrence Ndamka, Li Li, Sunny Chang, Ann Bolcavage
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Abstract
An article includes a substrate, a bond coat on the substrate, and a multilayer environmental barrier coating (EBC) on the bond coat. The multilayer EBC includes a first EBC layer defining a first thickness and a second EBC layer defining a second thickness. The first EBC layer includes a first rare earth disilicate and a first concentration of a sintering aid that includes alumina. The second EBC layer includes a second rare earth disilicate and a second concentration of the sintering aid that includes alumina, less than the first concentration of the sintering aid.
Claims18
An article comprising:
- a substrate;
- a bond coat on the substrate;
- a multilayer environmental barrier coating (EBC) on the bond coat, wherein the multilayer EBC comprises:
- a first EBC layer defining a first thickness, wherein the first EBC layer comprises a first rare earth disilicate and a first concentration of a sintering aid that comprises alumina, wherein the first concentration of the sintering aid is between 6 wt. % and 10 wt. %;
- and
- a second EBC layer defining a second thickness, wherein the second EBC layer comprises a second rare earth disilicate and a second concentration of the sintering aid that comprises alumina, less than the first concentration of the sintering aid, wherein the second concentration of the sintering aid is greater than 0 wt. % and less than 1 wt. %.
A method comprising:
- depositing a bond coat on a substrate;
- depositing a multilayer environmental barrier coating (EBC) on the bond coat, wherein the multilayer EBC comprises:
- a first EBC layer defining a first thickness, wherein the first EBC layer comprises a first rare earth disilicate and a first concentration of a sintering aid that comprises alumina, wherein the first concentration of the sintering aid is between 6 wt. % and 10 wt. %;
- and
- a second EBC layer defining a second thickness, wherein the second EBC layer comprises a second rare earth disilicate and a second concentration of the sintering aid that comprises alumina, less than the first concentration of alumina, wherein the second concentration of the sintering aid is greater than 0 wt. % and less than 1 wt. %.
Dependencies are inferred from the claim text.