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In order to modify the specific characteristics of graphite, different coatings and treatments can be applied.
We propose 5 types of coating and graphite impregnations for fine grain isostatic graphite (< 10µm) :
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Pyrolytic Carbon : with the use of high-temperature, high-pressure chemical vapour deposition, (CVD process), the ultra-pure pyrolytic carbon coating provides a smooth surface, high density, strength and hardness along with very low porosity making it virtually impermeable to fluids and gases. The coating thickness is typically 2 to 30 microns. Pyrolytic carbon coating is composed of 99.9995% elemental carbon and is virtually free of organic or metallic impurities. This process prevents the formation of SiC (Silicon Carbide) in contact with the silicon. The coating resists attack by hydrofluoric (HF) and most other acids. Thermal shock will not cause spalling, crazing or flaking of the coating. It is ideal for both semiconductor and solar applications. It is thermally stable and ideal for applications with temperatures up to 550°C in the presence of oxygen and up to 2500°C in vacuum or inert atmosphere.
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SiC : Also obtained using the CVD process, the SiC layer is 75 to 125 microns thick. This treatment can seal the graphite completely, the result being a high-quality tool that is virtually inert to all process gases and chemicals, with great hardness, resistance to oxidation and good thermal conduction.
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PTFE : We also provide PTFE treatments which increase resistance to acids, eliminating porosity while maintaining the thermal characteristics of the graphite.
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Methacrylate resin : Graphite can also be impregnated with this resin which will ensure that the graphite provides excellent sealant capacities.
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Antimony (only available for carbo-graphite) : Our graphite can be impregnated with antimony for applications where resistance to wear is essential.
Applications of graphite coating
- Dry lubrication for all materials
- Anti-seize agent for all materials
- Release agent
Graphite adhesives Resbond® 931
Our Cotronics® Resbond® 931 Adhesive bonds graphite or carbon components for use at temperatures up to 3000°C with 99% pure graphite. Just apply and cure at 120°C. Resbond® 931 has excellent adhesion to graphite, and other porous surfaces, forming graphite to graphite bonds with strengths over 17.5 N/mm². Resbond® 931 is ideal for repairing broken or cracked graphite trays, components, fixtures, dies; filling and rebuilding crevices, cracks, worn areas and bonding graphite cloths, felts, boards, etc.
Graphite spray 013-0001
Graphite spray is used for lubrication of metal, plastic or rubber parts without using grease. With this binder, it is possible to affix a film of graphite powder of very fine particle size with virtually no thickness on different materials.
Graphite coating is non permanent.
Graphite aerosol
FAQs that can help you in this category
Final Advanced Materials' Duralco high-temperature paints provide improved resistance to corrosion and adverse weather. The choice of paint will depend on the usage conditions and the material of the medium requiring protection. When the surface has been descaled, derusted, cleaned and degreased you can apply the paint using a brush or spray gun. Specifically: 2 thin layers are preferable to 1 thick layer.
If you require thermal resistance up to 650°C in a humid and/or saline atmosphere, the aluminium-based paint produced Final Advanced Materials offers would be a great solution. However, if the temperature requirement does not exceed 800°C, the Duralco 230 paint, which is stainless steel-loaded, would be more effective.
The ceramic coatings (BN or graphite) offered by Final Advanced Materials have low surface energy, which limits the adhesion of molten metals (Al, Zn, Cu, etc.). They reduce wetting and facilitate stripping. Their thermal stability and their chemical inertia improve the lifetime of the tools used. They also reduce metal contamination and wear of tools.
The coatings' maximum working temperature will depend on the gaseous environment. Temperature stability is limited to 450°C for graphite and 850°C for boron nitride in air or an oxidising atmosphere, and to over 1,000°C in a vacuum or inert gas.
The BN coatings offered by Final Advanced Materials can be applied with a spray, a brush or by dipping. Surface preparation (degreasing, roughness Ra 1.6–3.2 µm) is essential to provide a better adhesion. Drying is carried out at ambient temperature. The typical thickness is 10 to 50 µm. The thinnest possible layers should be used for application. Let each layer dry fully before applying a new one. If a layer is too thick it will have a lower resistance, and a higher risk of delamination or cracking. BN provides excellent thermal stability (as high as 800/900°C in air and 1,800°C in a vacuum or inert gas).
The anti-adhesion coatings offered by Final Advanced Materials provide very effective results in the glass industry. Applying a boron nitride-based product will result in a very low surface energy, an anti-adherent effect, high chemical inertia for silicate glasses, and high temperature resistance (≈ 900°C in air and up to 1,800°C in a controlled atmosphere). This coating will lead to a reduction in adhesion, decreased material transfer, and minimal surface marking.
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.