MICRO-INDENTATION BEHAVIOR OF HOPG INVESTIGATED BY EXPERIMENT AND MD SIMULATION

摘要

The mechanical behavior of highly oriented pyrolytic graphite (HOPG) is investigated by simulating the micro-indentation with the method of molecular dynamics and by doing indent experiments with the probe tip of atomic force microscope. The characteristics of graphite crystal lattice are discussed, and according to that, three potentials are selected for different interaction between graphite atoms in molecular dynamic calculations. In experiment, nano-indentation test by tip and consequential measurement are carefully operated by AFM. The topography of the hole indented by the tip, as well the profile, the surface state of the graphite, the indented force and the strength of HOPG are measured and calculated. Results show the indentation experiment and the MD calculation consistent-well with each other, that MD may be used as a good tool for comprehending the micro-mechanical behavior of a material.