Dislocation Nodes in Face-Centred Cubic Lattices

Deformation twinning in nanocrystalline materials

“…Therefore, we will only give a brief summary here. Coarse-grained fcc metals are believed to twin via several conventional mechanisms including the pole mechanism [71], prismatic glide mechanism [72], faulted dipole mechanism [73], or other mechanisms [74][75][76]. These mechanisms often require a dislocation source in the grain interior to operate.…”

Deformation twinning in bulk nanocrystalline metals: Experimental observations

“…Coarse-grained metals are believed to twin via conventional mechanisms including the pole, 29 prismatic glide, 30 faulted dipole, 31 and other mechanisms. [32][33][34] These deformation twins are formed by the glide of partials with the same Burgers vector on successive (111) planes. This collectively produces a net macroscopic strain, and inevitably changes the shape of the twinned grain as illustrated in Figure 6a.…”

Deformation twin formed by self-thickening, cross-slip mechanism in nanocrystalline Ni

“…This mechanism is very appealing to nanocrystalline fcc metals because they generally lack the continuous partial dislocation sources that are required for some twinning mechanisms of coarsegrained metals. [20][21][22][23][24][25] In addition, nanocrystalline materials have much higher strength than their coarse-grained counterparts [26][27][28] and, therefore, deform under very high stress. This high stress helps overcome the extra energy requirement for the dislocation reactions involved in the recently proposed cross-slip mechanism.…”