Effects of solutes on the thermal stability of nanotwinned materials

Nanoscale twins form in many metallic materials, especially those with low stacking fault energy. Their presence can significantly enhance the strength of a material. However, nanotwins are unstable and can be annihilated, e.g. by thermal annealing. We present the results of molecular dynamics (MD) simulations, which demonstrate that additions of solutes can significantly stabilize nanotwinned structures. The MD simulations reveal that the mechanism of the solute drag on the twin boundary may be associated not with the solute segregation on the incoherent twin boundary (ITB), but rather with changing of the ITB shape or position to accommodate as many solutes as possible.