Fabrication of isotropic bulk graphite using artificial graphite scrap

Fabrication of isotropic bulk graphite using artificial graphite scrap

Isotropic synthetic graphite scrap and phenolic resin were mixed, and the mixed powder was formed at 300 MPa to produce a green body. New bulk graphite was produced by carbonizing the green body at 700°C, and the bulk graphite thus produced was impregnated with resin and re-carbonized at 700°C. The bulk density of the bulk graphite was 1.29 g/cm3, and the porosity of the open pores was 29.8%. After one impregnation, the density increased to 1.44 g/cm3 while the porosity decreased to 25.2%. Differences in the pore distribution before and after impregnation were easily confirmed by observing the microstructure. In addition, by using an X-ray diffractometer, the degrees-of-alignment (Da) were obtained for one side perpendicular to the direction of compression molding of the bulk graphite (the “top-face”), and one side parallel to the direction of compression molding (the “side-face”). The anisotropy ratio calculated from the Da-values obtained was 1.13, which indicates comparatively good isotropy.