Quasicontinuum study on formation of fivefold deformation twin in nanocrystalline aluminum

The formation of a fivefold deformation twin in nanocrystalline Al is studied by the quasicontinuum method. The study focuses on the microstructural effect on the formation process. A particular low-index grain boundary, which has been investigated in a bicrystal model, is observed in the sample. The dislocation reflection and inhomogeneous stress distribution caused by this grain boundary are discussed. The importance of this microstructure to the formation of a fivefold deformation twin is manifested by the results.