Mechanical properties of pyrolytic graphite flakes

Abstract

Large graphite flakes (5–50 μm thick × 1–10 cm in length × ~ 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 l%–2% for strain at failure. The flexural strength of the graphite flakes rapidly increases from ~0.3 GPa for the 800°C product to 20 GPa at an HTT of 2600°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.