Graphite Coating – The Ultimate Guide

In the field of materials science, graphite coating technology helps improve the performance of materials. With its unique thermal, electrical, chemical and frictional properties, it is well suited to meet diverse industrial needs. And it plays a key role in many fields such as industrial manufacturing, electronics, and transportation.

What is Graphite coating?

Graphite coating is a functional film formed by coating graphite as the main component on the surface of various substrates by a specific process. Graphite is a crystalline mineral composed of carbon atoms, with a layered structure. This structure gives the graphite many unique physical and chemical properties, but also makes the graphite coating has the corresponding characteristics.

Characteristics of graphite coating

Lubricity:

The van der Waals force between graphite layers is weak, making it easy to slide relatively between layers. It can effectively reduce the coefficient of friction and reduce wear between mechanical parts.

Electrical conductivity:

This also makes it have potential application value in electronic and electrical fields. Such as the electrode coating of electronic components.

High temperature resistance:

The melting point of graphite is very high, and it can still maintain stable physical and chemical properties under high temperature environment. So the graphite coating can protect the base material under high temperature conditions.

Chemical stability:

It is inert to most chemical substances. And the graphite coating can enhance the chemical stability of the matrix material and improve its corrosion resistance.

Formation principle and common preparation method

The formation principle of graphite coating is mainly based on the physical or chemical bonding between graphite and the base material. Common preparation methods include:

Spraying method:

Mix the graphite powder or colloidal graphite with appropriate binder, sprayed to the substrate surface by spray gun. Then dry and cure it to form a coating. You can widely use it in the field of surface protection of large industrial equipment, such as storage tanks, pipelines, etc.. It can effectively provide protection for large area matrix.

Physical vapor deposition (PVD) method:

In a high vacuum environment, the graphite is evaporated or sputtered. So that its atoms or molecules are deposited on the surface of the substrate and condensed into a coating. This method can accurately control the thickness and quality of the coating. And the binding force between the coating and the substrate is strong.

Chemical vapor deposition (CVD) method:

This method decompose the gaseous carbon source at high temperature and under the action of catalyst. And carbon atoms are deposited on the surface of the substrate and react to produce graphite coating. The coating prepared by this method has high quality and good crystallinity, but the equipment is expensive and the process is complicated.

Type of graphite coating

Graphite powder coating

Graphite powder and binder mixed coating, it has low cost, simple process, for ordinary mechanical lubrication.

Colloidal graphite coating

Disperse graphite into colloidal coating, it has uniform dispersion, high quality, used in areas with high surface and performance requirements.

Pyrolytic graphite coating

High temperature pyrolytic organic carbon source film, high crystallinity and purity, used in aerospace and other high-end fields.

Graphite PVD coating

Prepared by physical vapor deposition, strong binding force, uniform thickness, controllable composition structure.

Graphite paint coating

Graphite powder and paint base mixed into paint coating, easy construction, decorative and protective, used for general industrial equipment protection.

Comparison with other coatings

Graphite coating vs. ceramic coating

The hardness and wear resistance of the ceramic coating is very high, excellent wear resistance, excellent performance under extreme wear. Although the graphite coating has a certain wear resistance, but the lubricity is its main advantage, which is better in reducing friction.

In terms of high temperature resistance, both are good, but the high temperature resistance limit of ceramic coating is higher.

In the application scenario. You can often use ceramic coatings in engine parts, cutting tools and other places that require high hardness and wear resistance. And you can mostly use graphite coatings in parts that need lubrication, conduction or work in a medium temperature environment.

Graphite coating vs. graphene coating

In terms of structure and performance, graphene is composed of a single layer of carbon atoms. It is a two-dimensional material with extremely high strength, electrical conductivity and thermal conductivity. Graphite coating is composed of multiple layers of graphite, which has different performance. But the cost and preparation process are more advantageous.

In terms of preparation cost, the high preparation cost of graphene restricts large-scale application. And the preparation cost of graphite coating is lower and easier to industrial production.

In the field of application, graphene has broad prospects in high-end electronic devices, sensors and other fields. And graphite coatings are widely used in industrial manufacturing, transportation and other fields.

Application of graphite coating

Graphite coating of metals

Graphite coating on steel

Coating it on the surface of steel can effectively improve the corrosion resistance and lubrication of steel. For example, in the production of automotive parts, graphite coating of steel parts can extend their service life and reduce maintenance costs.

Nickel coated graphite powder

As a special material, it combines the corrosion resistance of nickel and the lubricity of graphite. And you can often use it in the manufacture of high-performance bearings, gears and other mechanical parts.

Mechanical components

Graphite coating for mower deck

It can reduce the friction between the grass clippings and the chassis, prevent the grass clippings from sticking. And improve the efficiency of mowing.

Slip plate graphite coating

It can reduce the friction between the skateboard and the ground, making the sliding smoother.

Graphite coated wiper blades

It can enhance the wear resistance and lubrication of the wiper blade. To ensure that rain can be clearly scraped off under various weather conditions to improve driving safety.

Electronic field

Its conductivity makes it widely used in the field of electronics. For example, use it on the circuit board can improve the electrical conductivity of the line and reduce the loss of signal transmission. Use it on the heat sink of the electronic component can enhance the heat dissipation effect. And this can improve the working stability of the electronic component.

Transportation

Use it on piston and inner wall of cylinder of automobile engine can reduce friction and improve engine efficiency and fuel economy. Coating the wheels and track surfaces of rail transit with graphite can reduce wear and noise and extend the service life of equipment.

Graphite coating price

The price of it is affected by many factors, such as preparation method, coating thickness, and quality of graphite raw materials.

Spray graphite coating:

For general industry, 0.1-0.3mm thick per square meter, 7-70 USD, pricing according to graphite purity.

PVD graphite coating:

High-end manufacturing, 0.05-0.1 mm thick per square meter, 142-1400 USD, depending on the application field and raw materials.

CVD graphite coating:

Serving high precision fields, 0.01-0.05mm thickness per square meter, 430-1400 + USD, pricing according to accuracy requirements.

Conclusion

Graphite coating has high application value in industry, electronics, transportation and other fields. And it improves the properties of matrix materials by lubricating and conductive properties. With the development of technology, its preparation process will be improved, the cost will be reduced. And it is expected to expand its application and help the development of various industries.