Abstract
UDC 539.9:539.2:539.5
The paper deals with an investigation of mechanical properties and deformation peculiarities of polycrystalline copper and single-crystal LiF under dynamic nano-microindentation. It is shown that the value of hardness and Young's modulus depend on the magnitude of the applied load (Pmax): the higher the latter, the lower H and E. Common regularities that accompany the process of the indenter deepening in a wide range of loads are revealed. They are: the emergence of the “pop-in” effect at the initial stage of the loading process, the formation of more “pop-in” steps with the load increase, the formation of pile-ups around the indentations. Such behavior of deformation is the result of a sequential activation of different dislocation mechanisms at the indenter deepening. Along with a great similarity in the specificity of deformation, some differences were observed at the unloading stage. The results obtained are oriented on the comparison of mechanical properties of the Cu and LiF individual components with the same properties of the “coating/substrate” composite systems (CS Cu/LiF), created on their basis.
Keywords: mechanical properties, specificity of deformation, copper, LiF, dynamic indentation.