Electrochemically Facilitated Maintenance of Functional Coating Strip Solutions

ABSTRACT: There is a stated need for enhanced capabilities to strip functional coatings from, e.g., military aerospace parts, due to saturation behaviors exhibited by current stripping methods. In the proposed program, Faraday will develop low-cost, environmentally-sound drop-in/add-on unit operations based on pulsed FARADAYIC Stripping and ElectroWinning technologies, which would require only a power supply swap-out and installation of an auxiliary process tank, respectively. Faraday will establish processing conditions that allow for efficient FARADAYIC Stripping and FARADAYIC ElectroWinning recovery of dissolved metals, and evaluate the enhancement to stripping solution lifetime and processing rate afforded by this combination of technologies. We will identify suitable target operating metals concentrations to enable an appropriate balance of stripping rate/efficacy and electrowinning efficiency. We will initiate development of a transition plan for future implementation at Air Force and/or commercial partner maintenance facilities and perform an analysis of the economics, safety and material compatibility of the technology. Phase II will entail design and construction of a pilot-scale apparatus to strip coatings from specific aerospace parts of interest; evaluation of FARADAYIC Stripping performance on various substrate materials; development of alpha-scale components for prototype testing at Boeing and Air Force facilities; and completion of the technology transition plan. BENEFIT: The anticipated result of the proposed program is the demonstration, development and deployment of a low-cost, environmentally-benign augmentation of existing WC-Co HVOF stripping operations. In particular, application of pulsed FARADAYIC Stripping and Electrowinning technologies will be investigated for their capability to enhance stripping solution lifetime and enable recovery of dissolved metals. The process is scalable, will integrate directly with equipment available at USAF depots, and will result in significant cost reductions through extended lifetimes of stripping solutions and increased part stripping rates. Interest is also anticipated in the commercial aircraft market, as well as in any market segment in which wear-resistant coatings are needed, such as construction equipment, rail transportation manufacture, paper mill roll fabrication, and high-strength valve seals for undersea oil/gas extraction applications.