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 graphitescrap was compared with each other for different fiber content. The microstructure and properties of isotropic bulk graphiteaccording 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 manufacturedbulk graphite was confirmed using the analysis data of the X-ray diffractometer. By adding MCF 1 wt.%, it was possibleto improve the flexural strength (23.9 MPa) by 3.9%, while having the same level of density, shore hardness, and electricalconductivity. Furthermore, the volume shrinkage was decreased with increasing MCF content. However, compared to thepristine blocks, all of the main properties tended to decrease in the sample to which MCF was added more than a certainratio. There was no difference in the degree of alignment (Da) of bulk graphite according to the MCF content, and all samplesshowed an isotropic ratio. Fracture appearance and bonding state between fibers and carbonized phenolic binders wereobserved using SEM to examine the reason for the difference in the properties. In addition, the MCF arrangement in the bulkgraphite was non-destructively investigated using an X-ray microscope.