It produces dark gray to black crystalline structure on the surface. It has anti-friction character with a good wear resistance. It can be used either as an undercoat for powder coating or by applying suitable post treatments such as chromate sealing or oiling the life can be extended.
A fine silky texture to crystalline finish can be obtained ranging from light to dark gray in colour. This conversion process can be applied in steel and iron alloys, serves as an excellent bonding agent further process such as powder coating etc., Some advantages of zinc phosphate include uniform coatings, absorption and retention of organic materials and resistance to galling when used against other surfaces.
It can be done on any type of steel and iron alloys. It is a simple conversion by chemical process, which will yield a jet black finish with a post dip in oil, it improves the corrosion resistance.
In this process the copper and its alloys such as brass can be converted from light brown to black oxidized layer, to get an antique finish.
Aluminium can be converted to get a finish such as clear white, yellow and green colours by using suitable chromates. It can be used as an undercoat to powder coating for better adhesion and long life.
Electropolishing enhances the corrosion resistance, luster and smoothness of many metals and also effectively removes impurities leaving a homogenous metal surface. A widespread use of electro polishing is for enhancement in the appearance of a product. No other finishing can provide such a brilliant effect, and imperfections such as stains, heat discoloration, weld marks and minor scratches are eliminated or minimized.
Salt spray tests have proved that electropolished parts are four to five times more resistant to corrosion than untreated parts. Electro polished surfaces are stain and bacteria resistant to meet the exacting cleanliness standards of the food processing medical equipment.