In situ observation of stress induced grain boundary migration in nanocrystalline gold

In this study, the plastic behaviors of nanocrystalline Au with an average grain size of 18 nm were investigated in situ using a home-made tensile device in a transmission electron microscope. We provide the direct experimental results revealed the process of grain boundary migration. The results show that dislocation behaviors are prevalent for large grains. However, for grain sizes below similar to 15 nm, grain boundary migration occurs frequently. The results of our statistical analyses show that grain boundary migration occurs more frequently than grain boundary sliding and rotation in nanocrystalline Au. (c) 2017 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.