Evolution of the nickel structure during deformation by shear under high pressure at 150°C

Abstract

Initial single-crystal nickel deformed by shear under pressure at the temperature of 150°C has been studied. It has been found that, under these conditions, dynamic recrystallization develops in nickel. As a result, after true strain in the range of 4 < е < 9, a heterogeneous structure that consist of recrystallized grains of different defectiveness and microcrystallites is formed. Calorimetric studies have shown that the stored energy varies nonmonotonically with increasing true strain, which is associated with the cyclic character of dynamic recrystallization. In the calorimetric dependence, several peaks of heat release have been revealed that are connected with the nonsimultaneous occurrence of static recrystallization upon heating in nickel with a heterogeneous structure formed upon dynamic recrystallization.