Zinc phosphate is a crystalline conversion coating that is formed on a metal
substrate urilizing the chemical reaction between metal ions that have been dissolved
in mineral acids and then diluted with water to form the process solution.
Contrary to traditional plating operations where electrical current forces the
coating formation, zinc phosphating processes rely on the basic pickling reaction
that occurs on the metal substrate when the process solution comes in contact
with the metal. The mineral acids that are normally used to dissolve the metal
ions are nitric acid and phosphoric acid.