Advanced Aluminum Alloy Cleaning Methods for Improved Corrosion Resistance

The objective of the program is to demonstrate the feasibility of developing environmentally acceptable surface cleaning methods that increase the corrosion resistance of aircraft aluminum alloys. Existing specified cleaning processes degrade the corrosion properties of high-strength aluminum alloys due to formation of a copper-rich surface. Luna Innovations, Inc. will develop multiple cleaning environments and processes and quantitatively evaluate their impact on corrosion behavior of aircraft aluminum alloys. The Phase I will focus on demonstrating the selective removal and gettering, to prevent deposition, of alloying elements that degrade corrosion resistance, in particular copper. Chemical, mechanical and electrochemical means will be examined as methods to control the amount and electrochemical activity of copper and copper-bearing intermetallics on the cleaned surface. State-of-the-art electrochemical techniques will be used to quantify metrics of corrosion susceptibility that will facilitate objective evaluation of the various cleaning method. Evaluation will be done in comparison to a control cleaning method based on existing specified treatments.