Fretting Wear Elimination in Gear Box Housings

A new high-performance anti-wear coating is being developed under an SBIR program with the Air Force Research Laboratorys Materials Directorate for the Joint Strike Fighter. This coating is based on the Micro-Plasma Oxidation process, which is a high-voltage electrochemical process of oxidation which creates micro discharges on the surface of the part immersed in an electrolyte. This results in the creation of a nanostructured ceramic coating of a dense, ductile oxide layer. The oxide layer improves mechanical, wear, thermal, dielectric and corrosion properties of the surface. Test results under the Phase I SBIR program have shown a 10X improvement in wear life over the baseline. IBC Materials will apply the Micro-Plasma Oxidation process to repair worn-out missile launcher rails in combination with Friction Stir Weld and Cold Spray build-up processes to restore the missile rails to specified dimensions. IBC will also adapt and optimize a wear-protective coating based on the Micro-Plasma Oxidation process to improve the wear life of the rail. A localized coating fixture will be developed to allow coating of the missile rail outside of the bath and to avoid the need to mask the part. BENEFIT: The forward hanger and missile rail for the AIM-9X missile system are currently experiencing a large amount of fretting and galling wear due to excess vibration & play of the system. As a result several hundred missile rail units are scrapped each year due to excessive wear, costing the Air Force millions of dollars in parts and labor. A repair method to build the materials back to specified dimensions, as well as an improved protective coating, will restore the rails to full service life and possibly extend the life of the missile rails. This will result in a large labor and cost savings for the U.S. Air Force and U.S. Navy AIM-9X programs. These repair methods can also be applied to other DoD missile systems, as well as gearboxes, landing gear, pumps, and hydraulic equipment.