Effect of pore structure on the thermophysical and frictional properties of high-density graphite

Abstract

High density graphite is widely used in friction and sealing area. The pore structure inside, which were mainly affected by molding method, has a great effect on its thermophysical properties and friction performance. Herein, isostatic pressing, compression molding and hot molding method were utilized in our work to prepare high density graphite with different pore structure in order to study the relationship between pore structure and the comprehensive property. The results showed that the properties of graphite vary significantly in different directions, which was mainly affected by porosity, pore size distribution, the specific surface area, pore shape and fractal dimension. The influence mechanism of three graphite materials with different pore structures on thermophysical properties was delved, and the correlation between the comprehensive properties of graphite materials and their pore structures was verified. The in-plane comprehensive properties of hot molding graphite were the best, the graphitization degree was the highest (75.4%) and the total porosity was the lowest (15.08%). Especially, according to the pore structure analysis of the graphite, we found a positive correlation between the fractal dimension and the friction and wear properties of the graphite materials. Furthermore, research of pore structure explained the properties of graphite materials and proved the potential application of graphite in friction and sealing fields. • Graphite with different pore structures were prepared by different forming process. • The evolution of pore structure was deduced during the preparation of graphite products. • Pore structure characteristic parameters effect the comprehensive property of graphite. • Hot Molding can improve the orientation and degree of graphitization of the graphite. • Fractal dimension was positively correlated with the friction and wear properties.