Carbon materials belong to porous materials. The total porosity of carbon products is 16%~25%, and that of graphite products is 25%~32%. The existence of a large number of pores will inevitably have a negative impact on the physical and chemical properties and performance of carbon materials. For example, with the increase of porosity, the bulk density of carbon materials decreases, the resistivity increases, the mechanical strength decreases, the chemical and corrosion resistance deteriorates, and the permeability to gases and liquids increases. Therefore, for some high performance functional carbon materials and structural carbon materials, impregnation compaction must be implemented.
The following purposes can be achieved through impregnation and compaction treatment:
(1) significantly reduce the porosity of the product;
(2) Increase the bulk density of products and improve the mechanical strength of products:
(3) Improve the electrical and thermal conductivity of products;
(4) Reduce the permeability of the product;
(5) Improve the oxidation resistance and corrosion resistance of the product;
(6) The use of lubricant impregnation can improve the wear resistance of the product.
The negative effect of impregnation and densification of carbon products is that the coefficient of thermal expansion increases slightly.
Post time: Aug-26-2024