MECHANICAL-PROPERTIES OF PYROLYTIC-GRAPHITE FLAKES

Large graphite flakes (5-50-mu-m thick X 1-10 cm in length X approximately 1.5 cm in width) can be prepared via the decomposition of aromatic and heteroaromatic hydrocarbons. This work describes the dependence of the mechanical properties of benzene (B)- and pyridine (PR)-derived graphite flakes on heat-treatment temperature (HTT) and nature of precursor. The tensile strength and modulus of the flakes increase with increasing HTT, and are in the range 10-80 MPa for tensile strength, 5-10 GPa for Young's modulus, and 1%-2% for strain at failure. The flexural strength of the graphite flakes rapidly increases from approximately 0.3 GPa for the 800-degrees-C product to 20 GPa at an HTT of 2600-degrees-C. At low HTT, the tensile strength and strain to failure of PR-derived flakes are greater while at high HTT B-derived flakes are generally stronger than those derived from PR.