Contact of dissimilar metals (excluding aluminum and steel) should be avoided to lessen potential for what?

Contact of dissimilar metals should be avoided to lessen the potential for galvanic action, which occurs when two different metals are in electrical contact in the presence of an electrolyte. This contact creates a galvanic cell, leading one of the metals to corrode preferentially.

When dissimilar metals come into contact, their different electrochemical potentials can generate a flow of electrons, causing the more anodic (less noble) metal to lose electrons and corrode at an accelerated rate. This is particularly critical in electrical systems, where integrity and longevity are essential.

While oxidation can occur and may be linked to corrosion, galvanic action specifically pertains to the electrochemical reactions that occur due to differing metal properties. Likewise, the presence of electrical resistance is a separate phenomenon that does not directly cause corrosion between metals. Hence, understanding galvanic action is crucial for preventing damage in electrical connections and ensuring the durability of components made from different metals.