Early stages of recrystallization in nickel

Abstract

This paper reports on an investigation into the early stages of recrystallization in nickel from the standpoint of the misorientation between newly formed recrystallized grains and the surrounding deformed microstructure. For the case of recrystallization “nuclei”(i.e., <l-μm diameter), half the sampled interfaces were close to low-gS coincident site lattice (CSL) misorientations, particularly gS = 3. Established new grains(i.e., >l-μm diameter) tended to be either not low-gS CSLs or less close to a low-gS CSL than for the “nucleus” case. The interpretation of these data is that the very earliest stage of recrystallization is facilitated at a boundary which is more mobile than average, often a characteristic of a low-gS CSL. After nucleation of recrystallization has been established, the important criterion for the recrystallization interface is a large capacity for dislocation absorption, which is associated with general boundaries rather than CSLs. The number of boundaries bordering the new grains and their geometrical characteristics were consistent with a model which relates sides per grain to grain boundary energy.