Phosphate Coating and Phosphating

Phosphate Coating is a crystalline conversion coating that is usually formed through a ferrous metal substrate. The coating is applied for various purposes, but most especially for pretreatment, prior to coating and painting. As a result, the corrosion protection will be increase and the friction properties of the sliding components will be improved as well. In some cases, the Phosphate Coating is being applied to threaded parts and then top coated with oil so as to add anti galling as well as rust inhibiting characteristics.

 

The process of Phosphating would require relying on the basic pickling reaction which occurs on the metal substrate whenever the process solution would come into contact with the metal. Among the greatest benefits of Phosphating is on providing corrosion and adhesion protection. Generally, Phosphate Coating is being used on steel parts although it is sometimes used on aluminum on some other industries worldwide.

 

Manganese Phosphating

 

Sometimes, metal coatings would offer manganese phosphate coating when it comes to enhancing the corrosion protection, lubricity and anti galling of a material. Of all the various Phosphate Coating available, it is the manganese phosphate coatings that are considered the hardest. It is known to provide unbeatable abrasion protection and corrosion. As compared to zinc phosphate coatings, the manganese Phosphating is known to offer continued wear protection after it breaks down the components that are being subjected to wearing. Such coatings are being applied only through immersion. Other uses of manganese phosphate application would include production of bushings, bearings, fasteners and other commonly used industrial products. The use of manganese phosphate is indeed very useful on those projects that would require the sliding of parts, like the transmission systems as well as automotive engines.

 

Zinc Phosphating

 

The zinc Phosphate Coating is also used on several industries, mainly for rust proofing some ferrous metals. Such coating is applied by means of spraying and immersion and it is much lighter as compared to the manganese phosphate. It also provides resistance to several harsh elements which would often wear products easily.

 

The Phosphate Coating is usually made of thin crystalline layers of phosphate which adheres to the surface of the metal substrate. The phosphate crystals are usually porous in nature and can be formed from manganese, iron, zinc, and various phosphate solutions. Each of the three types offer phosphate coating that has slightly different properties, like the crystal size as well as the thickness of the coating. This is done in order to allow a more specialized coating to be chosen for a certain application that is needed for a particular component or parts. 

 

Zinc Phosphated Screws

 

The Zinc Phosphated Screws are often applied towards low alloy steel, carbon steel, as well as cast iron. The coating is being formed by means of spraying or by immersing the substrate towards a solution of dilute phosphoric acid that is then combined with other chemicals which assists on the Phosphate Coating process. The phosphoric solution of acid will then react against the metal used resulting to a mildly protective layer of crystalline phosphate.