Dynamic Polygonization in Nickel during High-Pressure Torsion

Using the Hollomon–Zener formalism and structural studies by the methods of transmission and scanning microscopy, we analyzed the variation in the structure of nickel in the course of deformation under pressure at 250°C. The effect of temperature and rate conditions of deformation on the structure-forming processes is shown. The ranges of true strain are established in which dynamic polygonization or dynamic recrystallization dominates in nickel. It is shown that at high-pressure torsion at 250°C, it is impossible to avoid development of dynamic recrystallization in nickel and obtain a structure formed only as a result of dynamic polygonization at a true strain of е > 2.7.