Process for coating aluminum and magnesium die casting bodies comprises electrolytically degreasing the body in an alkaline aqueous cleaner, descaling, forming a conversion layer, cataphoretically dip coating, rinsing in water, and curing

摘要

Process for coating aluminum and magnesium die casting bodies comprises electrolytically degreasing the die cast body in an alkaline aqueous cleaner; descaling; forming a conversion layer; cataphoretically dip coating; rinsing in water; and curing. The die cast body is bombarded with a potential before cleaning or has no potential. During degreasing, a polarity change takes place. The die cast body is descaled in an aqueous solution containing sulfuric acid before the conversion layer is formed. Preferred Features: The die cast body is electrolytically degreased either in an alkaline aqueous cleaner or in an alkaline fluoride-containing aqueous cleaner in a concentration of 0.5-10% using a current density of 0-12 A/dm2.