Titanium alkaline cleaning

Titanium is widely used in aerospace applications that require high strength-to-weight ratios at elevated temperatures. As a result, a number of different prebonding surface preparation processes have been developed for titanium. These generally follow the same sequence as for steel and other major industrial metal substrates degrease, acid-etch or alkaline-clean, rinse and dry, chemical surface treatment, rinse and dry, and finally prime or bond. Mechanical abrasion is generally not recommended for titanium surfaces. 

Turco Product Division, Purex Corporation. When combined with vapor degreasing and alkaline cleaning, this process offers very high-strength bonds on titanium. Plasa Jell is also a proprietary chemical marketed by Semco Division, Products Research and Chemical Corp. This formulation is available either as a thixotropic paste suitable for brush application or as an immersion solution for tank treatment. 

Panels of Ti-6-4 alloy adherend were obtained from the NASA-Langley Research Center. The panels were either used in the as-received condition or cleaned by the Pasa-Jell 107 method, a commercial process (American Cyanamid ) for cleaning titanium alloy surfaces. The primary steps in this cleaning process are, briefly sample immersion in degreasing 1,2-Tdichloroethane immersion in an alkaline cleaner, SPREX AN 9 solution pickling in an HNO3/HF solution and treatment with Pasa-Jell 107 (a chromate based acid paste). 

Removal of grease, oil, and other shop soils fi om titanium parts is normally accomplished with the same type of equipment and the same cleaning procedures used for stainless steel and high-temperature alloy components. Non-chlorinated solvents or alkaline deaners are recommended. 

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