Patent ID: 6339879
Filing Date: 2002-01-22
Classification: B21D,B23P,C23C,Y10T

Abstract:
A method of sizing and forming a cooling hole in a gas turbine engine component, the method comprising the steps of:forming a hole in a surface region of a substrate; measuring the thickness of any recast surface region surrounding the hole and created during the forming step as a result of the forming step having caused a portion of the surface region to melt and then resolidify; obtaining a gas turbine engine component having a surface region in which a cooling hole having a desired diameter is to be formed and on which will be deposited a diffusion coating comprising a diffusion zone that will extend into the surface region of the component and an additive layer that will deposit on the surface region of the component at a growth rate determined by a first set of deposition parameters; predicting a thickness of the additive layer of the diffusion coating on the component based on an inverse relationship between the thickness of the recast surface region of the substrate and the growth rate of the additive layer; forming a hole in the surface region of the component, the hole having a formed diameter that is larger than the desired diameter of the cooling hole; and then depositing the diffusion coating on the surface region of the component so that the additive layer grows sufficiently at the hole to yield the cooling hole approximately having the desired diameter.