Passivation

Passivation is the process where a relatively active surface that can corrode or stain is deliberately treated with chemicals to convert the surface to a passive one.

Passivates contain chromium compounds and are used extensively on zinc plated surfaces to extend the useful life of finished components. The colour of the chromate film changes as the film layer becomes thicker, from blue to yellow and through to olive / black.

Cleaning is the single most important stage in the electroplating process because absolutely grease free and oxide free surfaces are required for well bonded metallic deposits.

The variation of materials treated, their surface characteristics and the degree of contamination require the selection and co-ordination of effective cleaning and activation processes.