Superior thermal stability of coherent twin boundaries in nanotwinned metals

We compare the thermal stability of nanotwinned metals to their nanocrystalline counterparts. The thermal stability of a coherent twin boundary is superior to that of a high-angle grain boundary as the energy stored at twin boundaries is an order of magnitude lower than at high-angle grain boundaries. The stability of nanotwins sheds light on the use of these materials for relatively higher-temperature applications, where the retention of twins can enhance the mechanical strength of metallic materials. (C) 2012 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.