Mechanical and Electrical Properties of Milled Carbon Fiber Reinforced Artificial Graphite Scrap Composites with Phenol Resin as the Binder

Abstract

In the present study, the effect of adding milled carbon fibers (MCFs) to isotropic bulk graphite made using artificial graphite scrap was compared with each other for different fiber content. The microstructure and properties of isotropic bulk graphite according to the content of MCFs were investigated. The main characteristics were analyzed through the evaluation of density, volume shrinkage, flexural strength, shore hardness, and electrical conductivity. The anisotropic ratio of the manufactured bulk graphite was confirmed using the analysis data of the X-ray diffractometer. By adding MCF 1 wt.%, it was possible to improve the flexural strength (23.9 MPa) by 3.9%, while having the same level of density, shore hardness, and electrical conductivity. Furthermore, the volume shrinkage was decreased with increasing MCF content. However, compared to the pristine blocks, all of the main properties tended to decrease in the sample to which MCF was added more than a certain ratio. There was no difference in the degree of alignment (Da) of bulk graphite according to the MCF content, and all samples showed an isotropic ratio. Fracture appearance and bonding state between fibers and carbonized phenolic binders were observed using SEM to examine the reason for the difference in the properties. In addition, the MCF arrangement in the bulk graphite was non-destructively investigated using an X-ray microscope.