Method of removing excess overlay coating from within cooling holes of aluminide coated gas turbine engine components

A method of repairing a gas turbine engine component by removing excess MCrAIY overlay coating from within a cooling hole of an aluminide coated gas turbine engine component comprising the steps of:

• providing a gas turbine engine component having an internal surface, an outer surface and a root end, the component also having a plurality of cooling holes extending from the internal surface to the outer surface, wherein the internal surface of the component is coated with an aluminide coating, the component further including a MCrAlY overlay coating on the outer surface and inside a portion of the cooling holes;
• masking a portion of the cooling holes to prevent flow there through;
• inserting the component into an abrasive flow machining device;
• and
• forcing an abrasive slurry into the gas turbine engine component from the outer surface of the component to the internal surface of the component, through the cooling holes, wherein the slurry flows through the cooling holes and removes at least a portion of the overlay coating located inside the cooling holes without adversely affecting the aluminide coating on the internal surface of the component, such that airflow through the component is within design limits, +/-12.5 percent of a target nominal airflow level, the slurry subsequently exiting the repaired component through the root end.