Fig. 3
Typical example of coherent twin boundary sliding. a Experimentally measured mechanical response of the nano-twinned single-crystal Cu nanopillar subjected to compression along \({[1\overline 2 0]_{{\rm{M\& T}}}}\) orientation. The plot shows engineering stress as a function of loading displacement. Images b to d show dark-field TEM images of nano-twinned Cu compressed inside the TEM. Dark-field TEM image of Cu pillar b before and c after compression under [345]T beam direction, and d after compression under [211] beam direction. The inset denotes the selected-area diffraction pattern. e–h show the evolution of coherent twin boundary sliding (CTBS) as predicted by the MD simulation. e A \({[210]_{\rm{M}}}\) orientated Cu pillar (an equivalent orientation to\([1\overline 2 0]\)) created by MD simulation before tension. f A leading partial dislocation is nucleated and it propagates coherent twin boundary (CTB). g A trailing partial dislocation is nucleated and it propagates CTB. h A large surface step arising from coherent twin boundary sliding (CTBS). The scale bars in b, c, d represent 100 nm
