Economic Alternative to Wc-Co HVOF Composition for ID Applications for Landing Gear

ABSTRACT: Currently, the Unites States Air Force (USAF) Landing Gear community is implementing Electrolytic Hard Chrome plate (EHC) replacement for line of sight applications utilizing HVOF technology. The chemical formulations chosen for this application are WC-Co and Tungsten Carbide Cobalt Chrome (WC-Co-Cr). Due to the high hardness, grinding and finishing processes are more difficult for HVOF versus EHC. Tthe need exists for more economic alternatives suitable for the less demanding Inner Diameter (ID) applications. This project will focus on economical spall resistant, corrosion resistant, and seal compatible coating materials that will provide a valid replacement for expensive WC-Co ID repairs. The ES3 team has extensive experience in all aspects of landing gear & aircraft overhaul, and materials & processing for landing gear parts. There are two different technologies that ES3 will explore for the Phase I feasibility study of the SBIR. The two technologies are: HVOF-ID HVAF-ID 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 an economic coating process that can replace tungsten carbide coatings for ID"s of landing 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 either the HVOF-ID or the HVAF-ID systems coating 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 WC-Co. 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