Graphite block derived from natural graphite with bimodal particle size distribution

Abstract

This paper presents a novel method for the bimodal design of graphite blocks by optimizing the weight ratio of smallsized natural graphite (NG) particles (mean size of 5 μm) and large-sized NG particles (mean size of 500 μm). Graphite blocks were fabricated by subjecting a mixture containing large NG particles and a well-dispersed pitch/small-sized NG mixture (PSM) to pressure-mold heat treatment. The effect of the PSM contents on the structural, thermal, and mechanical properties of the graphite blocks was investigated. A correlation was found between the amount of small-sized NG particles, the micro-pore structure, and the distribution of large-sized NG particles. In particular, the graphite block, with small-sized NG particle content and pitch binder content of 21 wt% and 9 wt%, respectively, achieved maximum thermal conductivity and flexural strength values of 460 W m K −1 and 14 MPa, respectively, after pressure-mold heat treatment (graphitization) at 2600 °C. Our research advances the development of an eco-friendly solvent-free graphite block fabrication method that produces high-performance graphite blocks of varying size faster and more cost-effectively.