Phosphate coatings are often used to provide corrosion resistance and prepare surfaces for paint. The porous surface of the phosphate coatings allow them to combine with other sealers for desired properties and interlocking of paint when drying.
Fluoride Phosphate coating is used mainly on titanium. It improve paint adhesion, improves corrosion resistance, and also prevents fretting and galling for metal on metal contact.,
Zinc phosphates are commonly used on steel. It is used for corrosion resistance , a lubricant base layer, and as a paint base. Typically, it is applied by immersion.
Manganese phosphates are mainly used on steel. It is used both for corrosion resistance and lubricity and is applied only by immersion.