Corrosion Inhibiting Surface Treatment for Uncoated Marine-Grade Aluminum Alloys

Marine-grade aluminum alloys (5XXX-series) are increasingly being used in naval combatants because they have high strength and high corrosion resistance. In order to decrease weight these corrosion resistant marine-grade aluminum alloys are not painted with the conventional primer and low solar absorbance topcoat. The metal is simply blasted to keep it from being too shiny. However, without any coatings the unpainted aluminum metal is vulnerable to aging (including corrosion), it absorbs more heat (increasing ship air-conditioning costs), and it requires more maintenance to clean-up the ship"s appearance. Some protection of the marine-grade aluminum metal surface is still needed. Recently, TDA Research, Inc. (TDA) has identified organic inhibitors that have excellent activity on marine-grade Al5XXX, including arresting stress corrosion cracking. In this SBIR project TDA will develop a low VOC surface treatment containing these active corrosion inhibitors. This innovative, environmentally friendly surface treatment will provide corrosion protection, reduce thermal absorbance and leave a uniform haze gray color.