Maybe to many it's already quite clear: The cause might have been water
getting into the gap between the aluminum and stainless, thereby putting
an electrolyte (aluminum hydroxide) in a gap between two dissimilar
metals, which in turn set up an electrochemical cell that further
exacerbated the corrosion. On the other hand, I wonder if the bolts should
have provided an efficient current path between the Al and stainless (?)
Did water, however, get into the gap in the first place?
I have no definitive suggestions on how to deal with the corrosion on the
stainless, except to guess that maybe using an acid that would dissolve
aluminum oxide, but not stainless would work. Someone with more knowledge
of metallurgy would probably offer some good ideas.
Gregory R. Quinting, Ph.D.
Research Chemist, NMR
Sherwin-Williams Automotive Finishes Co.
Technical Center
10909 S. Cottage Grove Ave.
Chicago, IL 60628
(773)-821-2167
(773)-821-2263 (fax)
gregq@mcs.com
On Wed, 10 Sep 1997 bruins@indigo.ucdavis.edu wrote:
> Hi everyone.
> In the process of bringing up a 300 Mhz magnet we found severe corrosion
> on the aluminum base plate were it mates to the stainless steel can. The
> large Oring groove is mostly clean but the rest of the mating surfaces are
> severely corroded. Also this corrosion has atleast transfered itself to
> the stainless steel from which it is difficult to remove. Has anyone dealt
> with this problem before without having to replace the complete bottom
> plate. Any magic cleaning formulas perhaps? Any help would be greatly
> appreciated. Paul Bruins UC Davis.
>
>
>