With the continuous expansion of the application field of graphite materials, more and higher requirements are put forward for it. Therefore, it is necessary to introduce new supplementary process methods in industrial production in order to obtain products with special properties that cannot be obtained by ordinary methods. This process method is the compaction of carbon graphite materials.
Carbon graphite material is a kind of porous material. The densification process is to fill the pores or coating surface of carbon graphite material with different forms of carbon materials, or metals and alloys or other non-metallic materials. The purpose of the compaction process is mainly to improve the density, strength, electrical conductivity, thermal conductivity, corrosion resistance and wear resistance of the product. Sometimes, it is also to ensure that the product is impermeable to gas and liquid. However, there is a limit to compaction. It is impossible to require compacting all the pores of the product, but can only be compacted to a certain degree or a layer with a small depth of the product, or deposited on the surface of the graphite part. The covering layer can significantly change the performance of the part, because the deposited carbon layer becomes the working surface of the part.
Densification can include impregnation and surface treatment. Impregnation can be divided into liquid phase impregnation and gas phase impregnation. For liquid phase impregnation, it can be divided into: 1. pitch impregnation; 2. impregnation artificial resin; 3. Dipping grease; 4. Dipping metals and alloys; 5. Dipping inorganic compounds and other impregnants; 6. Dipping for special purposes. The surface treatment can be divided into surface coating and surface pyrolytic carbon deposition.
English
