The effect of twin plane spacing on the deformation of copper containing a high density of growth twins

In-situ tensile straining in a transmission electron microscope was used to investigate the role of twin plane spacing on the deformation and fracture mechanism of pure copper containing a high density of nanoscale growth twins. Real-time and post-mortem observations clearly reveal that twin plane spacing plays a key role in determining the operative deformation mechanism and therefore the subsequent crack propagation path. The deformation mechanism transition, which results from changes in the twin plane spacing, has implications for interpreting the unusual mechanical behavior of the copper with a high density of nanoscale growth twins.