Growth, Structure, and Properties of Graphite Whiskers

Abstract

Graphite whiskers have been grown in a dc arc under a pressure of 92 atmospheres of argon and at 3900°K. They are embedded in a solid matrix of graphite which builds up by diffusion of carbon vapor from the positive to the negative electrode. Diameters range from a fraction of a micron to over five microns, with recoverable lengths up to 3 cm. They consist of one or more concentric tubes, each tube being in the form of a scroll, or rolled‐up sheet of graphite layers, extending continuously along the length of the whisker, with the c axis exactly perpendicular to the whisker axis. They exhibit a high degree of flexibility, tensile strengths up to 2000 kg‐mm⁻², Young's modulus in excess of 7×10¹² dyne‐cm⁻², and values of room‐temperature resistivity of around 65 μohm‐cm, which approximates the single crystal value.