An Office of the Secretary of Defense effort is under way to establish a sophisticated turnkey repair station for magnesium alloy aerospace components using the highly successful cold spray technology developed with ESTCP support. The novel coating system represents a low-cost, environmentally friendly method for combatting corrosion and reclaiming otherwise unsalvageable magnesium components. The repair station will be the first single facility with the capability to perform all the operations required to restore these salvaged parts and will reduce repair time by up to three months.
Magnesium alloys are used to manufacture various aircraft components, including rotorcraft transmissions and gearbox housings. These alloys are susceptible to corrosion, which often leads to premature failure of the parts. Without the technology to adequately restore them, the corroded parts are removed from service and scrapped, at a cost of approximately $100 million per year.
The U.S. Army Research Laboratory, with ESTCP support, developed a cold spray process that involves accelerating aluminum alloy particles to high velocities and impacting them on the surface of magnesium alloy components. The technology was shown to provide surface protection and restore magnesium components that have been removed from service, earning an ESTCP Project of the Year Award in 2012. Implementation of cold spray for one UH-60 Blackhawk helicopter magnesium component has been approved by both the Sikorsky Aircraft Company and the Army Program Office. Approval of the technique is anticipated for the entire H-60 helicopter family.
Based on the success of the ESTCP demonstration, the project team transitioned the work to a Defense-wide Manufacturing Science & Technology (DMS&T) ManTech Program. The team will work with MOOG, Inc. to establish a turnkey repair station at its Webster, Massachusetts, location. The station will include a gantry robot and be based on a modular concept comprising the entire sequence of manufacturing operations required to perform cold spray repair of aerospace magnesium components. This sequence includes complete dimensional analysis, non-destructive inspection (NDI), blending/machining operations required to prepare the repair surface, the cold spray operation, final machining, and final NDI testing. Operators will only be required for initially affixing the part to be repaired and removing it once restored, helping to reduce repair time by two to three months.
Cold spray technology, whether incorporated into production or used for repair, can enhance operational readiness and result in significant cost savings for DoD.