Nanoindentation of ultra-hard cBN films: A molecular dynamics study

[Display omitted] •We optimize tersoff potential to better simulate the BN.•We perform respectively the nanoindentations on the (001) and (111) surface of cBN.•The main slip system of cBN under nanoindentation is {111} .•Temperature has a significant effect on the mechanical properties of cBN. Cubic Boron nitride (cBN) exhibits excellent mechanical properties including high strength, hardness and thermal resistance, etc. We optimized the parameters in the Tersoff interatomic potential for cBN based on its cohesive energy, lattice parameter, elastic constants, surface energy and stacking fault energy. We performed with molecular dynamics (MD) simulations the nanoindentation on the (001) and (111) surface of monocrystalline cBN thin films to study the deformation mechanisms and the effects of temperature and substrate orientation. It was found that during the indentation plastic deformation is mainly stress-induced slips of dislocations along {111} orientations. It was also found that the hardness of cBN depends strongly on temperature, and the capability of plastic deformation is enhanced with the increase of temperature.