Internal friction characterization of graphite

The effects of temperature on the damping behavior of bulk graphite were investigated and some novel phenomena were observed. The internal friction (IF) background of the bulk graphite has small temperature dependent and the IF value is much smaller than that of reported data. Moreover, two IF peaks were found in the IF-temperature spectrums. The first is proved to originate from the sweeping motion of in-plane dislocations and is a relaxation-type IF peak. The average activation energy of the peak is around 1.10 ± 0.06 eV and the pre-exponential factor s0 is 10-14 s. The second is a transformation peak, resulting from the transformation of asphalt that was used as binder in preparation of bulk graphite.