Structure of nickel–copper alloys subjected to high-pressure torsion to saturation stage

Abstract

Transmission electron microscopy and microhardness measurements were used to study the structure of Ni–Cu alloys subjected to high-pressure torsion (to saturation state) at room-temperature using five revolutions. It was shown that, when passing from copper to nickel, the submicrocrystalline structure becomes substantially refined, and the microhardness increases by more than 1.5 times. This is related to differences in the melting temperature and stacking fault energy. The simultaneous effect of these two factors leads to the nonlinearity of the composition dependences of the crystallite size and microhardness.