Patent ID: 6905730
Filing Date: 2005-06-14
Classification: C23C,Y02T

Abstract:
1. A method for forming a controlled, relatively uniform aluminide coating on a turbine engine component having an external surface and an internal cavity defined by an internal surface that is connected to the external surface by at least one hole, the method being conducted in a vapor coating container having a hollow interior coating chamber, the method comprising the steps of: (a) loading the coating chamber with the component to be coated; (b) heating the loaded coating chamber to a temperature of from about 240° C. to about 450° C.; (c) flowing a tri-alkyl aluminum coating gas into the heated coating chamber at a pressure of from about 50 to about 2000 mtorr (about 0.68 to about 27 kgf/m (d) heating the coated component in a a nonoxidizing atmosphere to a temperature of from about 500° C. to about 1100° C. to form an aluminide coating on the external and internal surfaces of the component, wherein the aluminide coating on the internal surface of the blade is less than about 0.003 inches (less than about 76.2 microns) thick in the airfoil body portion and less than about 0.0015 inches (less than about 38.1 microns) thick in the root portion.