Repair of aluminum alloy substrates is a mission essential maintenance activity across the United States Air Force (USAF) for maintaining warfighter readiness. 7075 aluminum alloy is a commonly used structural aluminum alloy used on many structural aircraft applications, including missile launch rails. Fretting commonly occurs in several areas across the launch rails due to dithering wear with the mating steel surface, resulting in premature condemnation of launch rails and necessitating repair at the depot level to increase mission capability. Multiple novel repair capabilities have potential with this failure mechanism. ? For this effort ES3 is proposing to explore multiple repair opportunities for 7075 aluminum alloy launch rails, including additive friction stir deposition (AFSD), friction stir welding in conjunction with thermal spray applications to prevent future wear of the repair, and bonding of wear resistant materials to prevent further wear. ES3 will accomplish this by taking two dimensional (2D) drawings and developing three dimensional (3D) models to machine simulated aircraft structures to perform the aforementioned three repairs. Prior to this ES3 will perform computational simulations using finite element analysis (FEA). These repairs will then be characterized by performing structural mechanical testing to ensure integrity of the repair.
