Kinetics of Grain Growth upon the Heating of Nickel Deformed by High-Pressure Torsion

Scanning electron microscopy has been used to study recrystallization processes during the annealing (to 16 h) of nickel with cellular, mixed, and submicrocrystalline structures formed by high-pressure torsion deformation. Annealing in a temperature range of 200–350°C failed to produce a recrystallized structure with an average grain size of smaller than 1 μm. The smallest recrystallized grain size was found in the submicrocrystalline (SMC) nickel structure after annealing at 300°С. The SMC structure was formed via deformation to e = 9. The kinetics of normal grain growth was not implemented during the annealing of SMC nickel. The nonmonotonic size dependences of recrystallized grain on the temperature and annealing time in the SMC nickel are analyzed.