Formation of annealing twin boundaries in nickel

The development of annealing twin boundaries in pure nickel was investigated using instantaneous heating in a salt bath and in situ annealing on a heating stage designed for use with electron backscatter diffraction. It was observed that twin grains form to assist in the recrystallization process and that a significantly higher fraction of twin boundaries form when the deformed specimen is heated at a slow rate, regardless of the annealing temperature. (C) 2014 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.