Metallic article having a thermal barrier coating and a method of application thereof
AssigneesROLLS-ROYCE plc, Chromalloy United Kingdom Limited
InventorDavid S Rickerby
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Abstract
A metallic article includes a bond coating and a ceramic thermal barrier coating on the bond coating. The ceramic thermal barrier coating includes a plurality of columnar grains, which extend perpendicularly to the surface of the metallic article. Each columnar grain includes a plurality of layers. Some of the layers include sub-grains extending at an acute angle to the surface of the metallic article to form voids between adjacent sub-grains. The voids are arranged at an acute angle to the surface of the metallic article and reduce the thermal conductivity of the ceramic thermal barrier coating. Some of the layers include sub-grains extending perpendicularly to the surface of the metallic article to provide erosion resistance.
Claims37
A metallic article comprising a bond coating on the metallic article and a ceramic thermal barrier coating on the bond coating, the ceramic thermal barrier coating comprising a plurality of columnar grains extending substantially perpendicularly to the surface of the metallic article, each columnar grain having a plurality of layers having sub-grains extending at an acute angle to the surface of the metallic article to form voids between adjacent sub-grains, the voids being arranged at an acute angle to the surface of the metallic article and thereby reduce the thermal conductivity of the ceramic thermal barrier coating.
A method of applying a ceramic thermal barrier coating to a metallic article, comprising the steps of:
- forming a bond coating on the metallic article, applying a ceramic thermal barrier coating to the bond coating by vapour deposition such that a plurality of columnar grains extend substantially perpendicularly to the surface of the metallic article, the vapour deposition process including a first deposition mode comprising depositing the ceramic such that a plurality of layers are formed in each columnar ceramic grain, the plurality of layers having sub-grains extending at an acute angle to the surface of the metallic article to form voids between adjacent sub-grains, the voids being arranged at an acute angle to the surface of the metallic article and thereby reduce the thermal conductivity of the ceramic thermal barrier coating.
Dependencies are inferred from the claim text.