High temperature spherical nano-indentation of graphite crystals


Magnification of the sample at 0 5um and 600 degrees celsius

The deformation mechanisms of graphite have been investigated using nano-indentionals at up to 600 degrees Celsius in highly orientated pyrolytic graphite, studied by cross-sectional dark field scanning transmission electron microscopy.  

This finds an increased tendency at high temperature for inelastic deformation by buckling of the graphite crystals with kink formation, and may explain the increase in strength of polycrystalline at high temperatures.

The study, published in Carbon, was a collaboration between Professor James Marrow, Professor David Armstrong of this department, and Dr Ivo Sulak (Institute of Physics of Materials, Czech Academy of Sciences, Brno).