A theoretical model is suggested which describes generation of nanocracks in nanotwinned metals during their plastic deformation occurring through stress-driven widening of nanoscale twins in nanotwinned metals. In the framework of the suggested model, widening of pre-existent growth twins under mechanical load carries plastic deformation and leads to formation of wedge disclination structures at junctions of twin and grain boundaries. These disclinations create high local stresses capable of inducing nanocrack generation. The conditions for such a crack generation in nanotwinned metals are calculated. |
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