Inconel Blisk Repair Technology

State-of-the-art military turbine engines incorporate Integral Bladed Rotors (IBR), which are one piece components consisting of blades and a disk (blisks), in the compression system. Their purpose is to reduce weight through part count reduction and improve performance and maintainability. However, to maintain affordability, the need for weld repairs of either partial or full blades is warranted to avoid expensive IBR/blisk replacements resulting from foreign object damage (FOD) to the airfoils. No adequate technology exists today to repair fielded engines. For alloys commonly used in fans and compressors, current pre- and/or post-weld heat treatment practices, as part of the repair of airfoils, result in unacceptable micro-structural degradation in the highly stressed disk portion of the IBRs/blisks. Exposing the undamaged airfoils to needless heat treatment at every repair leads to significant reduction in their structural capability. Thus a novel and enabling weld repair technology that will permit independent repair and optimization of airfoil and disk material properties is proposed to retain and restore the high cycle fatigue (HCF) characteristics of IBRs/blisks. The proposed technology has the potential to meet these requirements in addition to addressing affordability and maintainability requirements of advanced military propulsion power plants.