Manganese Phosphate Coatings
Manganese phosphate coating (also known as black phosphate coating) is generally used for metal parts operating in oily environment in the automotive, machinery manufacturing and defense industry. When used with lubricants, beside its anti-corrosion properties it minimizes metal-to-metal friction wear.
Black phosphate coating, whose main content is manganese, is especially used in engine, gear and power transfer systems to increase the sliding effect. Manganese phosphating provides significant protection for gearbox gears, differential gears, camshafts, valves, pistons and parts, brake and clutch parts, various springs and many other auto parts like this.
Manganese phosphating can be used in all products that are required to provide high corrosion resistance in the metal processing industry. It can be applied to many metal parts and equipment such as drill bits and drilling elements, nuts and screws, tooling tools. Manganese phosphate coating is also made on many parts in compressors, oil pumps and hydraulic systems.
It is a type of coating that takes place in military standards in the defense industry (MIL-DTL-16232-G).
Manganese phosphate coating line can be formed from 5-6 baths or as a detailed system with 15-16 baths. The coating is applied by dipping. Its color is more close to black.
Activation is used just before manganese phosphating. It is important to use activation to obtain a coating with uniform and fine crystal structure that meets corrosion resistance standarts. The use of activation makes it possible to carry out the phosphating process at lower temperatures. Activation is also required for hard steel parts that are difficult to coat.
All technical details regarding the operation of the treatment line are provided by our technical support for the desired coating weight, coating thicknes, oiled or non-oiled corrosion and salt spray test resistance.
Manganese Phosphate Coating Products and Chemicals
The concentrated coating chemical product is usually clear green in color. It is sold in acid-resistant plastic drums or IBC tanks. Activation and acid regulation additives are powder products and are sold in 25 kg sacks.
One-component product for iron, steel and cast parts used by dipping method. Depending on use of activation, the coating weight is 15 - 25 g/m2 and the coating thickness is 5 - 25 microns. It has the advantage of working at low temperatures when used with activation pre-rinse. Provides high corrosion resistance in accordance with the standards.
It is a slightly alkaline product in powder form that is used just before the manganese phosphating treatment. It makes it possible to obtain a good coating on hardened or highly alloyed steel materials that are difficult to coat. Provides fine crystalline coating with low thickness to meet the standards requiring high corrosion resistance.
Manganese phosphate coating product that can be used in low concentrations compared to standard products suitable for iron, steel and casting. It is applied by dipping. Provides coating in the range of 10 - 20 g/m2. Higher corrosion resistance coating is obtained with the use of activation.
Acid regulating additive product used in manganese phosphate coating baths. The total acid/free acid balance must be ideal for problem-free continous working. Used to correct the acid imbalances in the phosphating solution caused by properties of the coated parts and working temperature.
Manganese Phosphate Coating Images
Image of manganese phosphate coated surface; It varies according to the color of the metal itself, the type of acid used in the preliminary stage and working conditions, whether activation is used, the coating temperature and the additives of the phosphating chemical. Appearance can be obtained in the range of anthracite to dark black. It gets darker and brighter after protective lubrication.
Friction Resistant Manganese Phosphate Coating On Steel
Metal Surface Treatment - Phosphate Coating Images
Notes:
* Images of the same metal part; not coated (left) and manganese phosphate coated.
* The coating was made with product PHORYL M 70.
* Coating weight is 16 - 20 g/m², coating thickness is about 10 µm.
Activation Conditioning Effect for Black Manganese Phosphate Coating
Metal Surface Treatment - Phosphate Coating Images
From left to right, in order:
* Untreated metal workpiece.
* Thick crystalline manganese phosphate coated workpiece, without activation.
* Fine crystalline manganese phosphate coated workpiece, with activation.
Black Manganese Phosphate and Protective Oiling
Metal Surface Treatment - Phosphate Coating Images
From left to right, in order:
* Untreated metal workpiece.
* Manganese phosphate coated workpiece.
* Manganese phosphate coated + protective oiled workpiece.