Non-aqueous Environmentally Benign Surface Preparation for Aluminum Pre-treatment Processes

An environmentally benign surface preparation process is proposed for aluminum alloy pre-treatment prior to coating and paint application. Surface preparation of aluminum is a critical factor affecting the performance of subsequent corrosion resistant coatings. Arcane methods of surface preparation are currently employed that have been followed by the Navy for many years. These techniques require the use of toxic chemicals that are dangerous to workers health, and at the same time, are very expensive to employ. The proposed treatment process is based on the use of atmospheric pressure oxygen plasma to clean and activate bare aluminum surfaces on aircraft components. Atmospheric pressure plasma is an effective way to remove residual carbon contamination and generate surface functional groups for adhesion. The plasma based surface preparation will replace hazardous cleaning, etching, and de-oxidizing processes with a dry process that uses no toxic chemicals, does not produce hazardous waste, and will yield a much higher level of cleaning and priming than current practice. In addition, chemical precursors will be added to the plasma to produce super tough sol-gel-like coatings that can act as a corrosion inhibitor and paint primer.