Non-Line of Sight Coating on High Strength Steel Substrate

ABSTRACT: There is a current need to remove the use of EHC on landing gear component bores (non-line of sight). EHC has been utilized on landing gear components for numerous years. There are many benefits to EHC such as providing an excellent wear surface, a good corrosion barrier and it allows for surface restoration to dimensional tolerances during the repair and overhaul process. EHC also provides a good sealing surface for hydraulic fluid as well as nitrogen. However, due to EHC environmental and health hazard risks, the Under Secretary of Defense has directed all DOD Military Departments to invest in appropriate research and development on EHC substitutes and approve the use of alternatives where they can perform adequately for the intended application. ES3 has been under contract with the USAF executing a large scale, multi-year effort implementing HVOF thermal spray coatings on HSS landing gear line of sight applications. However, landing gear components are still required to utilize EHC on non-line of sight areas and is in need of technology which will replace EHC for this application. There are three unique technologies that ES3 will explore for the Phase I feasibility study. The three technologies are: Rotary Plasma Magnetron Sputter HVOF-ID The objective of this effort is to demonstrate the feasibility of applying a wear and corrosion resistant coating to HSS-IDs for the purpose of removing EHC. More specifically, numerous tests will be performed on the applied materials to show that the applied coatings possess the qualities necessary to make it an acceptable material. The chosen system and material can be specified for standard maintenance at USAF Air Logistic Centers (ALC"s) and Navy Air Depots. BENEFIT: Research conducted to develop a coating process which can restore steel IDs of worn or damaged land gear components, focuses on military applications; however, benefits will be similar for all commercial & military landing gear that need IDs restored to original dimensions. ES3 expects the following benefits from Rotary Plasma, Magnetron Sputter, or HVOF ID systems restoring the ID of steel landing gear components based on both industry and in-house research: Non-line of sight surfaces of worn or damage IDs can be restored to serviceable condition in place of EHC. Increased supportability of steel landing gear parts for USAF and commercial industry Reduction in ownership cost for the USAF and commercial industry Processes could be used to repair other aircraft parts including hydraulics