Zinc phosphating is a process where a fairly even crystalline coating of zinc phosphate is applied to mainly steel and iron components either by immersion or spray. The colour of the deposit ranges from a light to dark grey and can be dyed black giving a matte finish.
What Is Zinc Phosphating?
Zinc Phosphating produces a smooth, uniform coating that will most often be used as a carrier for lubricants, anti-corrosion waxes and paint.
What Is The Process?
Zinc Phosphating can be applied through immersion in a tank or through a spray. Phosphating is a conversion coating so where electro-plating is adding material above the surface, phosphating is changing the makeup of the material surface. The component comes into contract with a phosphoric acid and a chemical conversion takes place which forms a layer of insoluble zinc phosphate crystals. This crystalline structure on the surface has many peaks and recesses and it is within these microscopic recesses that oils and waxes can be carried.
What Are The Advantages?
Zinc Phosphating provides a good level of corrosion resistance with low friction which will inhibit galling. Its primary function is as an undercoat or carrier. Some noticeable applications include as a carrier for lubricants in cold forming operations such as tube and sheet drawing. As a carrier for rust inhibiting solutions in particular to improve the corrosion resistance of the coating. As a carrier for anti-friction coatings such as molybdenum disulphide. Zinc Phosphating is most often used on steel and iron materials.
DEF STAN 03-11/1 Class II, BS 3189:1973 Type 1B (on hot and cold rolled steel)
What We Offer:
Zinc Phosphating on components up to 1500mm x 500mm x 900mm
Silchrome Plating are full ISO 9001 and 14001 certified and carry out all of our processes in house at our modern production facility in Leeds, West Yorkshire.