Restoration of Dimensional Tolerances

ABSTRACT: When the inner diameter (ID) of a landing gear aluminum alloy outer cylinder is damaged or worn there is very little that can be done to restore the ID of the cylinder. Consequently, the outer cylinder has to be condemned and taken out of service. A coating repair for aluminum alloy cylinder IDs that builds thickness, which can be machined to size, would be of great value to the United States Air Force (USAF). ES3 has completed a considerable amount of testing in both Phase I and II to develop a Magnetron Sputtering System (MSS) process for use in repair of the ID of aluminum landing gear outer cylinders. Results of testing have shown the MSS performed very well in all of the testing and has great potential to be used in repairing oversized aluminum alloy landing gear outer cylinders. Phase II.5 will include additional ID wear and load testing, a complete update of prototype equipment, installation cost study, sputtering specification draft as well as initiate performance tracking of sputtered components. This Phase II.5 effort will prepare for Phase III activities that will focus on the implementation of the MSS process. BENEFIT: ES3 expects Phase II.5 tests and PTP to show that ID sputtered aluminum alloy is a perfect material for rebuilding inner diameters of cylindrical aluminum alloy aircraft parts. The Plug & Coat Deposition device, however, is not limited to applications of aluminum alloys. Almost any metal or alloy may be deposited on the internal diameter of cylindrical parts. This ability allows a number of important applications in the civilian sector to be commercialized. The magnetron sputtering process can also be used to sputter chrome onto the ID of steel outer cylinders. Sputtering can be used to apply coating of several metallic materials such as nickel, titanium, aluminum, steel, etc. Chromium replacement is even more important now, as the EPA significantly reduced the hexavalent chrome personal exposure limit (PEL) in January 2006 to a level that requires the hexavalent chrome plating process to be replaced or drastically reduced. With little alteration, the coating equipment built in Phase II.5 can be used to demonstrate ID chromium replacement for numerous products in numerous arenas. Oil well sucker pumps have cylindrical pump barrels that historically have chromium plated IDs. A ceramic chromium material can be sputtered on the pump barrels ID in lieu of chrome plating. Use of such an ID material is expected to increase oil well sucker pump lifetime by a factor of 5 or more. This is important to oil well production economics because the removal and replacement of sucker pumps, many times from more than 10,000 feet in depth, is an expensive operation. Increased lifetime for these pumps lowers the cost of oil from well production.