I am fascinated by the concept of dissimilar metals and galvanic corrosion.
I stayed up until 3:45 am last night surfing the web to learn more. Of course I’m lying, but we do field questions about galvanic corrosion. Robbie Huffman, Samtec’s Interconnect Processing Engineer, recently shared some information on this subject with our Field Sales Engineers. I hope you find it helpful:
When choosing connectors for your application, it is important to choose mating connectors with similar plating materials in the contact areas. Dissimilar metals in the contact areas (i.e. gold mating with tin) can result in galvanic corrosion. Galvanic corrosion is an electrochemical process in which one metal corrodes preferentially to another when both metals are in electrical contact, in the presence of an electrolyte.
The chart below shows how different plating materials react to one another with regard to their galvanic potential. The larger the absolute value of the number at the intersection of the two plating materials, the larger the potential for galvanic corrosion. If the number is highlighted in green, that combination of materials has a low galvanic potential and is preferred. If the number is highlighted in yellow, the combination is less than optimal but still acceptable. If it is not highlighted, the potential is high and this combination should not be used.