Abstract

Metals, important materials for construction and manufacture, corrode in certain environments limiting the lifetime of manufactured metal goods. To protect from corrosion and to confer paint adhesive properties to metal surfaces, chemical pretreatment conversion coatings are widely used.

The most common metal surface treatments are iron, zinc, or chromium phosphating, chromating, and anodizing. An overview of the mechanism of coating formation, process operation and control considerations, coating characteristics, coloring procedures, and important applications for various coatings is given. Environmental considerations for chemical conversion coatings and by-products of conversion coating operations are also discussed.