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Overview of carbon-graphites
Carbon-graphites have a fine or very fine particle size and can have a very high degree of anisotropy due the axial process. They are composed of graphite with an impregnation of amorphous carbon.
These materials are designed with specific properties in terms of tribology and electricity which can be reinforced through impregnations with resins or phosphates. Unlike traditional graphites, carbo-graphites are not very good thermal and electrical conductors.
We stock 3 references of carbon-graphite:
- EK24 (without impregnation)
- EK2240 (phenolic resin impregnation)
- EK305 (antimony impregnation)
A product that is 100 % graphite is relatively soft, whereas the addition of amorphous carbon makes the product very hard. It becomes therefore impossible to machine with high-speed steel tools; ideally, it should be machined with a diamond tool. Similarly, carbo-graphite is less resistant to extreme termperatures compared to pure graphite.
Key features of carbon-graphite
- Excellent corrosion resistance
- Very good mechanical strength
- Good sliding properties
- High thermal shock resistance
- Low wettability
- Anti-wear
- Long-term stability
- Adaptable properties (depending on the impregnation product)
- Can operate dry without lubrication or in a wet environment
Applications of carbon-graphites
- Sealing rings
- Sealing gasket for agitators and autoclaves
- Bearings
- Pumps for hot/cold water, fuels, chemicals
Feel free to contact us so that we can evaluate your specifications and assist you in choosing the most suitable carbo-graphite for your application. Based on your plans, we also offer a complete machining service for your parts, from prototyping to high-volume production.
If our carbo-graphite characteristics do not meet your application requirements, Final Advanced Materials also offers the option to produce parts in materials such as silicon carbide, zirconia, or boron nitride, for example.
Technical data of carbon-graphites
|
Properties |
EK24 |
EK2240 |
EK305 |
|
|
Impregnation |
No impregnation |
Phenolic resin |
Antimony |
|
|
Density |
g/cm3 |
1.70 |
1.8 |
2.55 |
|
Flexural resistance |
MPa |
60 |
70 |
80 |
|
Compressive strength |
MPa |
180 |
200 |
290 |
|
Young’s modulus |
GPa |
18 |
19 |
21 |
|
Rockwell B hardness |
105 |
110 |
115 |
|
|
Thermal conductivity |
W/m.K |
14 |
15 |
33 |
|
Linear expansion (20/200°C) |
10-6.K-1 |
4.1 |
5.0 |
6.0 |
|
Temperature resistance |
°C |
350 |
200 |
500 |
FAQs that can help you in this category
Graphite can withstand different temperatures depending on the atmosphere in which it is used. Its working environment directly affects its thermal performances.
In a vacuum or an inert atmosphere, graphite can withstand extremely high temperatures, even above 2,000°C. If oxygen is not present, the material retains excellent thermal and structural stability.
In air or an oxidising atmosphere, however, the maximum working temperature is lower. At around 400 to 500°C and above; graphite starts to oxidise gradually on contact with oxygen, leading to a degradation of its properties and loss of material.
Choosing the right graphite grade and considering the atmospheric conditions in which the graphite will be used is absolutely necessary to obtain the performance and lifetime needed for a given application.
The Final Advanced Materials team is at your disposal to help you choose the most suitable graphite solution based on your thermal and environmental constraints.
Due to its layered crystalline structure, graphite has excellent electrical and thermal conductivity properties.
This organisation facilitates the movement of electrons and the propagation of heat within the material.
However, graphite also has anisotropic properties: its conductivity varies depending on the direction of the crystalline layers. Conductivity is thus higher in the direction parallel to the layers than in the direction perpendicular to them.
Parameters such as the graphite's purity and density also influence its electrical and thermal characteristics. All these characteristics therefore determine the level of conductivity of the material.
Despite these variations graphite remains an excellent thermal and electrical conductor, which is particularly suited to many demanding industrial environments.
The Final Advanced Materials team is at your disposal to help you choose the most suitable graphite for your technical requirements.
Graphite is an excellent solution for aggressive chemical environments.
Due to its great chemical stability, it resists most acids and bases, including at high concentrations.
Unlike metals, graphite does not rust and does not dissolve in most corrosive environments, making it a material which is particularly suitable for demanding applications.
However, there are certain limitations which be taken into account. In the presence of oxygen and high temperature, graphite is subject to oxidisation which can impair its properties. In addition, in fluorinated environments, in particular in the presence of hydrofluoric acid, a direct chemical reaction with carbon can occur.
The choice of graphite and working conditions therefore depends on the application's chemical and thermal environment.
The Final Advanced Materials team is at your disposal to help you choose the best graphite for your technical requirements.
A graphite-loaded cement is a particularly suitable solution for repairing graphite parts.
Its chemical compatibility with the material, along with its thermal expansion and electrical conductivity, which are similar to those of graphite, make it a preferred solution for this type of application.
Ceramic-loaded cements are particularly recommended for localised repairs which do not require high a mechanical strength.
The Final Advanced Materials team is at your disposal to help you choose the best solution for your technical constraints.
Graphite naturally possesses lubricating properties which is one of its most widely acknowledged characteristics.
Due to its layered structure, where the different layers easily slide over one another, it is an excellent solid lubricant.
However, its performance can vary depending on the working environment. In an inert atmosphere or in a vacuum, its effectiveness diminishes due to the scarcity of gas and moisture, elements which make it easier for the graphite layers to slide over one another.
However, in an oxidising, high-temperature atmosphere the main challenge is its natural oxidisation, which can impair the graphite’s properties.
The choice of graphite therefore depends directly on the working conditions and on the constraints specific to your application.
The Final Advanced Materials team is at your disposal to help you select the graphite solution which is most effective and best suited to your needs.