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AssigneeGeneral Electric Company
InventorsBangalore Aswatha Nagaraj, Jeffrey Lawrence Williams, John Frederick Ackerman
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A protective coating system and method for protecting a thermal barrier coating from CMAS infiltration. The coating system comprises inner and outer alumina layers and a platinum-group metal layer therebetween. The outer alumina layer is intended as a sacrificial layer that reacts with molten CMAS, forming a compound with a melting temperature significantly higher than CMAS. As a result, the reaction product of the outer alumina layer and CMAS resolidifies before it can infiltrate the TBC. The platinum-group metal layer is believed to serve as a barrier to infiltration of CMAS into the TBC, while the inner alumina layer appears to enhance the ability of the platinum-group metal layer to prevent CMAS infiltration.
A component having a thermal barrier coating on a surface thereof, the component comprising a protective coating system overlying the thermal barrier coating, the protective coating system comprising inner and outer alumina layers and a platinum-group metal layer encased therebetween.
A gas turbine engine component having a thermal barrier coating of yttria-stabilized zirconia, the component comprising an outer protective coating system overlying the thermal barrier coating, the protective coating system comprising a platinum-group metal layer encased between inner and outer alumina layers having columnar grain structures, such that platinum-group metal is not present at an external surface of the component defined by the protective coating system.
A method of protecting a thermal barrier coating on a surface of a component, the method comprising the step of depositing a protective coating system on the thermal barrier coating, the protective coating system comprising an inner alumina layer deposited on the thermal barrier coating, a platinum-group metal layer deposited on the inner alumina layer, and an outer alumina layer deposited on the platinum-group metal layer so that the platinum-group metal layer is encased between the inner and outer alumina layers.
A method of forming a protective coating system on a thermal barrier coating of yttria-stabilized zirconia that is present on a gas turbine engine component, the protective coating system defining an external surface of the component, the method comprising the steps of:
Dependencies are inferred from the claim text.