Which of the following is a nonelectrolyte chemical treatment for aluminum that increases corrosion resistance and paint-bonding qualities?

• A. Anodizing
• B. Alodizing
• C. Passivation
• D. Chromating

Answer: (B)

Alodizing is a nonelectrolyte chemical treatment that forms a protective aluminum oxide coating without using electrical current. This oxide layer boosts corrosion resistance and creates a porous surface that takes primer well, enhancing paint-bonding qualities.

Anodizing, in contrast, uses an electrical current in an acid bath to grow a thicker oxide layer. Chromating coatings often involve an electrolyte bath as well to convert the surface, and passivation mainly focuses on reducing surface reactivity rather than optimizing paint adhesion.