Development of Nanosteel Chrome Replacement HVOF Coatings on High Strength Steel Components

ES3 has completed a SBIR Phase I effort of a feasibility study for the research and development of Nano-composite High Velocity Oxygen Fueled (HVOF) coatings for replacement of hard chrome plating on high-strength steel landing gear components.The Phase I work focused on finding an HVOF coating that will be more resistant to spallation when subjected to high-bending stress loads on landing gear components, verses the current HVOF coating of Tungsten Carbide Cobalt (WC-Co) and Tungsten Carbide Cobalt Chrome (WC-Co-Cr) coatings.4 Nano-composites were deemed suitable for both overhauled landing gear components as well as newly-manufactured components.These candidates are proposed to begin Phase II testing for qualification and implementation.BENEFIT:Research conducted for chrome plating replacement with HVOF Nano-composite coatings on HSS material, such as 300M (280-300 KSI) are primarily used on Landing Gear components.Benefits will be similar for all aircraft and engine usage for replacement of chrome plating where spallation concerns for high stresses, especially under bending occur where current wear and corrosion protection needs exist.HVOF Nano-composite coatings meeting the original equipment requirements for fatigue, bending stress, wear and corrosion properties have several advantages over chrome plating.While providing a higher quality finish for components, improved process times and environmental safety improvements are also evident.The following demonstrate benefits ES3 expects from use of HVOF nanosteel coatings in lieu of chrome plating based on both industry and in-house research:Improved wear resistanceImproved corrosion resistanceIncreased fatigue lifeImproved thermal properties(i.e. grinding burn resistance)Improved rework allowance for sealing high pressure nitrogen (no mud cracking)Improved repair coating thicknessEliminated hydrogen embrittlementImproved process timeIncreased service lifeImproved environmental concernsUtilize same grinding wheel as HSS substrate for machiningReduced spallationReduced cost of nanosteel powders compared to common HVOF WC-Co and WC-Co-Cr powders