Calculation of Dynamic Hardness by Molecular Dynamics

Abstract

Based on the molecular-dynamic simulation of the impact of a solid ball on the surface of polycrystalline copper, a method for calculating the dynamic hardness of nanocrystalline materials is proposed. It is proposed to carry out the calculation of hardness by dividing the impact work by the squeezed volume. It is shown that this expression of dynamic hardness is consistent with Meyer hardness in the case of quasistatic indentation. As a result of this simulation, it is shown that under conditions when the diameter of the impactor decreases and approaches the crystal lattice constant of the target, the dynamic hardness increases. Also, in the calculations, the impactor density varied approximately twice, which was equal to the density of steel and the density of tungsten carbide. For a striker diameter of 5 nm, dynamic hardness increases with the speed of the striker and does not depend on its density.