What is the nonelectrolyte chemical treatment for aluminum alloys that increases corrosion resistance and paint-bonding qualities called?

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

Answer: (A)

Alodizing is a chemical conversion coating for aluminum that does not use electricity. It forms a protective aluminum oxide layer by immersion in a bath, which increases corrosion resistance and provides a surface that paints bond to more readily. This non-electrolytic process is different from anodizing, which grows oxide through electrical current and tends to produce a thicker coating. While chromating and passivation coatings also improve corrosion resistance, they typically involve chromium compounds or different surface chemistries. The essence here is a nonelectrolyte treatment that enhances both protection and paint adhesion, which makes alodizing the best fit.