Which statement best describes the effect of Alodine on aluminum alloy?

• A. A slightly rough surface
• B. Increased corrosion resistance
• C. A smooth painting surface
• D. Relieved surface stresses

Answer: (B)

Alodine is a chromate conversion coating applied to aluminum alloys. It chemically transforms the surface to a layer of chromium compounds that passivates the metal, providing a substantial increase in corrosion resistance, especially in demanding environments. This protective coating also creates a better base for paint primers, helping adhesion.

So the primary benefit you’re looking for is the enhanced corrosion resistance. While Alodine can aid paint adhesion, the option describing a smooth painting surface isn’t the main effect, and it doesn’t relieve surface stresses.