Metal Phosphating

Description

Phosphating of metal – the process of forming a film of phosphates on the metal surface.

Our Technical Capabilities for Phosphating

Sizes of Processed Parts:

— Rings, gear wheels, drilling locks, flanges, etc., with a diameter of up to 500mm;

— Shafts, extensions, studs, etc., with a length of up to 600mm;

Weight of processed parts – up to 100kg

Sizes of Processed Parts:

— Rings, gear wheels, drilling locks, flanges, etc., with a diameter of up to 500mm;

— Shafts, extensions, studs, etc., with a length of up to 600mm;

Weight of processed parts – up to 100kg

Purpose of Phosphating

Surface phosphating of iron alloys changes the state of the surface and enhances:

Friction Reduction Properties: Improves anti-friction characteristics of the metal.
Electrical Insulation Properties: Enhances the electrical insulation properties of the metal.
Anti-Galling Properties: Increases the resistance to galling or seizing of the metal.
Paint Adhesion: Improves surface adhesion for painting.
Corrosion Resistance: Enhances the corrosion resistance of the material.

Phosphating is carried out in a solution of primary metal phosphates, usually iron, manganese, or zinc, in water at temperatures ranging from 86°C to 98°C for 40-80 minutes, depending on the metal being processed.

Phosphating is used to apply phosphate coatings to metallic products to impart additional corrosion protection, electrical insulation properties, and as a primer for further painting processes, as the phosphate layer has excellent adhesion to the surfaces of the processed items.

The phosphating layer is well-regarded for rust protection.

In practice, there are hot and cold phosphating methods:

Hot Phosphating: Used for protective coatings on machine parts and other industrial applications.
Cold Phosphating: Suitable for treating parts using spray methods or when heating the parts is undesirable. Coatings obtained from cold solutions are amorphous and suitable only as a primer for painting.

To achieve a high-quality, uniform phosphate coating, parts must be thoroughly cleaned, degreased, and free from dust and dirt. The surfaces can also be treated with sandblasting or shot blasting equipment. With proper cleaning, a dense coating layer of 5-10 µm is formed on the parts.

MAIN STAGES OF MANUFACTURING PARTS SUBJECT TO PHOSPHATIZING

Rough mechanical processing.
Preliminary heat treatment of the metal (known as thermo-enhancement), including two operations — hardening and tempering. This treatment ensures high toughness and strength of the core of the part. Steel hardening is carried out at high temperatures (850-950˚C) followed by cooling in oil or water. Tempering temperature depends on the requirements for the parts.
Final mechanical processing of the part, including metal grinding. These operations are necessary to ensure that the part has the required (final) geometric parameters.
Surface preparation. Degreasing with organic solvents promotes the formation of fine-grained coatings, while the use of strongly alkaline degreasing or etching leads to the formation of coarse, large grains.
Protection of metal surface parts that should not be subjected to phosphating. This is achieved by coating with liquid glass or tin plating, applied to a thickness of no more than 0.015 millimeters on the workpiece using electrolytic technology.
Direct application of the phosphate coating — phosphating.

Phosphating of Metal

— is the process of forming a protective layer on a metal surface, typically consisting of metal phosphates such as zinc, manganese, iron, or calcium. This layer is created through a chemical reaction between the metal surface and a phosphate solution, which is applied to the metal by immersion, spraying, or brushing. Phosphating of metal has several functions:

Firstly, it improves the adhesion of paint and other coatings, providing a more durable and aesthetically pleasing finish.
Secondly, phosphating creates a protective layer on the surface that prevents corrosion and wear of the metal, especially in conditions of high humidity or aggressive environments.
Thirdly, phosphating can serve as a base coating before additional treatments, such as the application of iron phosphate or powder coating.

Phosphating of metal is widely used in various industries, such as automotive, machinery, electronics, and other sectors where protection of metal parts from corrosion and wear is required, as well as improvement of their appearance. It is especially common in the production of cars and other vehicles, where metal parts must withstand extreme operating conditions such as severe impacts, high humidity, and temperature fluctuations.