Cleaning Q&A: Cleaning Beryllium Copper for High Vacuum

Q. I would like your input for cleaning beryllium copper to be used in an ultra high vacuum systems. I have access to ultrasonic tanks, DI water systems and more. Is there a procedure to follow to remove hydrocarbons?

A. I do not have any direct experience in the cleaning of beryllium copper, however, beryllium forms oxides very readily (similar to aluminum). A beryllium copper alloy will also include a small amount of beryllium oxide that will reform on the surface in air and cannot be reduced in even the best vacuum systems. So I will assume that you are not interested in effectively and permanent removing any oxide that may be present, but only organic residues.

For oil removal, it is best to use a solution that will mitigate the potential formation of copper oxides since these will be chemically reduced in an ultrahigh vacuum. A highly caustic aqueous cleaner, with a significant amount of dissolved oxygen will tend to oxidize the copper portion of the beryllium copper alloy. Measures typically taken to clean copper are to use solvent cleaning or an aqueous cleaner with moderate alkalinity which will effectively remove processing lubricants while minimizing excessive oxidation. The use of the equipment mentioned above (ultrasonic tanks and deionized water systems) will enhance and/or shorten the overall cleaning process.

Originally published in the October 2015 issue.