Abstract: A method of removing hot corrosion products from the surface of a component exposed to corrosive conditions at elevated temperatures, as is the case with turbine, combustor or augmentor components of gas turbine engines. The method is particularly suited for the removal of hot corrosion products from components protected with a diffusion aluminide coating, either as an environmental coating or as a bond coat for a thermal barrier coating (TBC). The processing steps of the method include immersing the component in a heated liquid solution containing acetic acid, and then agitating the surfaces of the component while the component remains immersed in the solution. In this manner, hot corrosion products on the surfaces of the component are removed without damaging or removing the diffusion aluminide coating. As a result, regions of the component from which the hot corrosion products were removed can then be repaired by a suitable aluminizing process.

Abstract: A method of removing surface dirt and contaminants from a component, such as a turbine, combustor or augmentor component of a gas turbine engine. The processing steps generally include soaking the component in a solution containing acetic acid, agitating the surfaces of the component such as with ultrasonic energy, and then rinsing the component of the acetic acid solution. A preferred acetic acid solution is vinegar either diluted by water or used full strength. Preferably, the component is also immersed in a solution containing acetic acid during the agitation step. The treatment steps can be performed at room temperature for durations of as little as two hours. The method is particularly suited for the removal of silica and calcium-containing compounds from air-cooled components protected with an environmental coating such as a diffusion aluminide coating.

Abstract: A method for repairing a turbine engine airfoil having an environmental resistant coating on a outer wall surface includes selecting and masking a discrete portion of the airfoil outer wall surface to protect the coating on the selected discrete portion, thereby providing a masked outer wall surface and an unmasked outer wall surface. The coating is removed from the unmasked outer wall surface, the maskant is removed, and the airfoil is repaired.

Abstract: A method for repairing a damaged tip of a turbine engine member, for example a tip of a high temperature operating turbine blade, having a designed length and an environmental resistant coating at least on an outer wall of the member and extending at least onto the tip, includes removing the damaged tip without first removing coating, on a wall adjacent the tip. This provides a preform end surface to which is bonded a replacement tip material having a second length greater than the designed length. Then a portion of the replacement tip material is removed to provide the member with a repaired member tip and of substantially the designed length while retaining the coating on the wall adjacent the repaired tip.