Development of Pulse Water Strip of Tungsten Carbide HVOF Coatings and Chrome Plating on Landing Gear Components

ABSTRACT: Chrome plating has been utilized for Aircraft, Landing Gear, Engine and Propeller components for over half a century, and High Velocity Oxygen Fuel (HVOF) tungsten carbide (WC-Co, or WC-Co-Cr) coatings are currently being utilized for chrome replacement on many aerospace components and implemented on many non-aerospace applications. Aircraft, Landing Gear, Engine and Propeller components are typically made of High Strength Steel (HSS), Low Strength Steel (LSS), Inconel 718, Titanium, Aluminum and other alloys, and are very sensitive to processing techniques. Currently, surface finishes such as chrome plating and Thermal Sprayed Coatings (such as HVOF WC-Co or WC-Co-Cr) coatings are stripped using wet chemical baths (or mechanical means) at overhaul. However, both processes require different chemical solutions or mechanical processes that can be harmful to the substrates during processing. This proposal will discuss the research and development, future qualification requirements, and related concerns that will utilize an environmentally and process friendly, pulse water strip system to remove both platings and thermal sprayed coatings (and other organic and inorganic coatings) applications on aircraft, landing gear, engine and propeller components. BENEFIT: The research discovered from removing chrome plating and thermal sprayed coatings on Aircraft, Landing Gear, Engine and Propeller components will benefit the military and commercial world usage of HSS materials, such as 300M (280-300 KSI), LSS materials, such as 4340 (180-200 KSI), Inconel 718, titanium and other alloys. ES3 expects the following benefits from use of the pulse water strip system on plating and coatings, based on both industry and in-house research: Utilization of one pulse water strip system in lieu of separate wet chemical baths and mechanical techniques for the removal of plating and thermal spray coatings. Elimination of hydrogen embrittlement. Elimination of arc or grind burn damage. Improvement of environmental concerns. Elimination of relief bakes. Improved process times. Utilization of basic water (no abrasives) in a recycled system.