Grain growth phenomena in nickel

Abstract

It is common to make a distinction between normal and anomalous grain growth based on the form of the grain size frequency distribution. For normal grain growth, the distribution approximates to log normal, whereas anomalous grain growth is characterized by a distribution skewed towards large grains. Although anomalous grain growth is generally associated with particle-restrained microstructures, there is evidence of its occurrence in pure metals, which is inconsistent with classical theories for the mechanism of anomalous growth. The objective of the present work was to investigate the grain growth response of nickel (99.5% and 99.999% pure) at several temperatures. The temperatures were chosen to coincide with a range which has been previously observed to induce changes in grain boundary properties. This work is a subset of a much wider study program to elucidate the factors which control grain boundary migration and related properties.