a study on the effect of coke particle size and applied compacting pressure on the physical properties of electrographite brushes

In this study, electrographite brushes were produced from petroleum coke and coal tar pitch via the powder metallurgy method, and the effect of petroleum coke particle size and applied compacting pressure were investigated on the green density, hardness and, the graphitization process. the results showed that an increase in the density of the raw sample and the hardness of the final product occurred due to a decrease in particle size by increasing the milling time up to 4 h. additionally, an increase in both density and hardness of the sample was observed as the applied compacting pressure was increased up to 150 mpa, where no alteration in the obtained values was observed with a further increase in the applied pressure. as a result of increasing the milling time and applying the optimum pressure, the density of the raw sample increased to 1.41 g/cm³ and the hardness increased to 81 shore c. the results also proved that the average particle size of the used petroleum coke and the applied compacting pressure do not have an influence on the graphitization process.