Cleaning and Pre-treatment Processes for Aerospace Titanium and Super Alloys Utilizing Environmentally Sustainable Surface Preparation Chemicals

Titanium, Inconel, and other super alloys are used in specialized application in the aerospace industry. These alloys are often the only materials that can be heat treated to achieve the mechanical properties and weights required for the associated specifications. Proper surface cleaning and preparation of these aerospace materials are critical for performance, long-term functionality, bonding and bond strengths. Performance data for an environmentally sustainable surface cleaning and preparation process for these materials will be presented. Prior art has been complicated by the difficulty in removing the oxides associated with the heat treatment process. This challenge has been met by the use of hazardous materials such as hydrofluoric or chromic acids. These chemicals pose extreme hazards for operators and pose risks for the companies performing the processes. The novel process developed reduces the cost of application, improves operator safety, and uses environmentally sustainable chemistries. Non-hazardous chemicals and a simple waste stream are critical for process sustainability and operator safety. The described surface pre-treatment has successfully been applied to Inconel and Titanium alloys. The prepared surfaces exhibit stable surface cleaning, de-oxidation, surface appearance and stability of substrate chemical composition. The cleaning solutions are capable of multiple uses or single use to disposal. Current testing has only used immersion cleaning, but spray methods can be developed. Test results will be presented.