Patent ID: 7270764
Filing Date: 2007-09-18
Classification: C23F,F01D,F05D,Y02T,Y10T

Abstract:
1. A used turbine engine blade having a metal-based substrate and an aluminide coating on at least one internal surface of the airfoil portion of the blade and at least one external surface of the airfoil portion of the blade, and wherein at least a portion of an aluminide coating has been selectively removed from at least one internal surface of the root and shank portions of the blade with negligible effect on the aluminide coating on the internal and external surfaces of the airfoil portion of the blade by a method comprising the following steps: (a) contacting the at least one internal surface of the root and shank portions of the blade with at least one stripping composition comprising from about 20% to about 40% nitric acid, by weight of the composition, at a temperature less than about 20° C. for at least about 2 hours to degrade the coating without damaging the substrate; and (b) removing the degraded coating without damaging the substrate.