Ask the Expert Question-and-Answer Archive

by Ron Joseph

February, 2006

Surface Treatment for Aluminum Alloys

Q. Please suggest a suitable surface treatment methodology for the Aluminum alloy which shall need to withstand 200 - 400 hours of salt spray test.

A. The most effective method is to chromate conversion coat the aluminum. Typical conversion coatings include Alodine and Chemfilm, both of which are trade names. If you do not want to use chromate-containing pretreatments, then you can consider non-chromate treatments, but their service life is less. You will find that Henkel http://www.surface-technologies.com/int_henkel/hst/index.php makes Alodine and Chemetall-Oakite http://www.oakite.com/ makes Chemfilm.

Unfortunately, I can't answer your question in more detail in the short time available to me, but if you would like you work with me on a consulting basis I can go into much greater detail and give you the pro's and con's of each option and help you select the best process for your specific products and for your production line.

Please get back to me if you would like to pursue this further.

Best wishes,

Ron Joseph