With the continuous expansion of the application field of graphite materials, more and higher requirements have been put forward for it. Therefore, it is necessary to introduce new supplementary process methods in industrial production to facilitate the acquisition of products with special properties that cannot be obtained using ordinary methods. This process method is the compaction of carbon graphite materials.

Carbon graphite material is a porous material, with a densification process that involves filling the pores or coating surface of carbon graphite material with different forms of carbon, metal, alloy, or other non-metallic substances. The purpose of densification process is mainly to improve the density, strength, conductivity, thermal conductivity, corrosion resistance, and wear resistance of the product, and sometimes to ensure that the product is impermeable to gases and liquids. However, there is a limit to compaction, and it is not possible to require all the pores in the compacted product, but only to a certain degree or a layer of product depth that is not deep, or to deposit on the surface of graphite parts. Its covering layer can significantly change the performance of the part, as the deposited carbon layer becomes the working surface of the part.

Densification can include impregnation and surface treatment, and impregnation can be divided into liquid phase impregnation and gas phase impregnation. For liquid phase impregnation, it can be divided into: 1. impregnation with asphalt;

2. Immerse in artificial resin;

3. Soak in oil;

4. Immersion of metals and alloys;

5. Immerse inorganic compounds and other impregnating agents;

6. Special purpose impregnation.

For surface treatment, it can be divided into surface coating and surface pyrolysis carbon deposition.