Changes in Mechanical Properties of Graphite Blocks Fabricated Using Natural Graphite as a Filler by Adding 3-mm Chopped Carbon Fiber

The present study examined changes in the mechanical properties of natural graphite-based graphite blocks resulting from the addition of 3-mm chopped-carbon fiber (cCF). 0–1.2 wt.% of cCF was added as a filler to a mixture of natural graphite, and phenol as a binder. The amount of natural graphite was reduced with increasing content of cCF. The obtained mixture was subjected to uniaxial compression molding and then carbonization in an inert atmosphere to fabricate graphite blocks. As the cCF content of the graphite blocks increased from 0 wt.% to 1.2 wt.%, their density decreased while the porosity increased. Overall, the addition of cCF led to an improvement in the mechanical properties of the graphite blocks; the best performance was achieved when the cCF content was 0.8 wt.%. Its hardness and flexural strength were improved by about 27% and 60%, respectively.