Galvanic corrosion at the interface of a dissimilar metal part may best be prevented by which measure?

Galvanic corrosion at the interface of a dissimilar metal part may best be prevented by which measure?

• A. coating with wax
• B. lubrication
• C. metal-to-metal contact
• D. a nonporous dielectric material between the surfaces

Answer: (D)

Galvanic corrosion happens when two different metals touch in an electrolyte, causing electrons to flow from the more anodic metal to the cathodic one and the anodic metal to corrode. The most effective way to prevent this is to insert a nonporous dielectric barrier between the surfaces to electrically insulate them, stopping the galvanic current. Coatings like wax or lubrication don’t reliably stop the electrical connection or ion transfer over time, and allowing metal-to-metal contact would keep the galvanic interaction going. A nonporous dielectric barrier blocks both electron flow and ion passage, preventing the galvanic couple from forming.

Galvanic corrosion happens when two different metals touch in an electrolyte, causing electrons to flow from the more anodic metal to the cathodic one and the anodic metal to corrode. The most effective way to prevent this is to insert a nonporous dielectric barrier between the surfaces to electrically insulate them, stopping the galvanic current. Coatings like wax or lubrication don’t reliably stop the electrical connection or ion transfer over time, and allowing metal-to-metal contact would keep the galvanic interaction going. A nonporous dielectric barrier blocks both electron flow and ion passage, preventing the galvanic couple from forming.