TURBINE COMPONENT COOLING HOLE WITHIN A MICROSURFACE FEATURE THAT PROTECTS ADJOINING THERMAL BARRIER COATING

摘要

Cooling holes in a turbine component, such as a blade, vane or combustor transition, are formed in and surrounded by a micro surface feature (MSF) that protects the adjoining thermal barrier coating (TBC) from delamination or crack propagation during the hole formation or during engine operation. The MSF effectively functions as a circumferential sleeve around the cooling hole margin so that relatively more friable TBC material that would otherwise define the cooling hole margin is not directly exposed to coolant fluid exhausting the hole, foreign object damage (FOD) or contact with cooling hole formation tooling when fabricating the hole through the TBC layer. The MSF is formed as a projection from the component substrate or during subsequent application of a metallic bond coat (BC) layer.