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Stopping galvanic corrosion of dissimilar metals that must be electrically connected

2004

WHAT WOULD BE THE BEST METHOD OF SEPARATION OF DISSIMILAR METALS WITHOUT REDUCING ELECTRICAL PERFORMANCE (CONDUCTIVITY BETWEEN MATING SURFACES)BETWEEN 6061-T6 ALUMINUM WITH CHROMATE CONVERSION COATING PER MIL-C-5541 [affil link], CL3 AND BRASS OR COPPER?

DOMENICK SIGNORINO
MICROWAVE FILTERS - EDINBURG, VIRGINIA, USA

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First of three simultaneous responses -- 2004

A thin coat of electroless nickel on the brass part should not affect the conductivity too much. If it does, gold plate the brass part, or possibly only the contact face. This is a labor for masking vs cost of plating the entire brass part tradeoff.

James Watts
- Navarre, Florida

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Second of three simultaneous responses -- 2004

Virtually impossible to do. The fundamental requirement for galvanic corrosion is for there to be a good electrical path between the two metals so that the corrosion circuit can be made between the two metals. I would suggest you think about alternative metals. The only way you will prevent galvanic corrosion is by ensuring the metals do not corrode (i.e., keep them in a totally inert environment)

Trevor Crichton
R&D practical scientist
Chesham, Bucks, UK

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Third of three simultaneous responses -- 2004

If you need Microwave continuity and not necessarily DC continuity, use a 1/4 wave choke as you would in rotating joints.

Tom Gallant
- Long Beach, California USA