Dislocation assisted crack healing in h-BN nanosheets.

Large size h-BN nanosheets are usually polycrystalline in nature and contain different types of grain boundaries. The low angle grain boundaries are usually referred as dislocations. The interaction of dislocations with the defects present in materials may affect the properties of materials. The aim of the current atomistic simulations was to study the effects of 5|7 dislocations on the mode-I fracture toughness of h-BN nanosheets. Molecular dynamics-based simulations were performed with different sets of geometrical configurations of dislocations in conjunction with centrally embedded cracks in h-BN nanosheets. Our results predicted an excellent improvement in fracture toughness values that range from 11% to 74% for h-BN nanosheets in the presence of defects. The improvement in the fracture toughness of h-BN nanosheets was attributed to the interaction of dislocation and crack stress fields. Considering the bright scope of h-BN nanosheets as a substrate in graphene-based nanodevices and as filler in nanocomposites, our study may be helpful for further technological developments.