In situ observation of twin boundary migration in copper with nanoscale twins during tensile deformation

Abstract

In situ transmission electron microscopy observations are reported of the dynamic process of twin boundary migration in Cu with nanoscale twins. The experiment provides the first direct evidence of twin boundary migration via Shockley partial dislocation emission from the twin boundary/grain boundary intersections, and reveals that such migration is the dominant deformation mechanism in the initial stage of plastic straining. The behaviour is discussed in comparison with molecular dynamics simulations and in terms of the unique characteristics of the sample microstructure.

Acknowledgements

This work was supported by the National Nature Science Foundation of China, Grant No. 50125103, the Hundred Talents Project and the MANS Research Team funded by the Chinese Academy of Sciences. The authors thank Xiao Si for sample preparation and Profs. H.Q. Ye and S.X. Mao for helpful discussions.