Abstract: The mechanical behavior is an important factor that affect its application, and the Al nanowire with high stacking fault energy usually displays different deformation mechanisms comparing with other FCC metal nanowires. Thus, the mechanical behavior and deformation mechanism of Al nanowire along different crystal orientations are investigated by molecular dynamics simulation, and they are compared with other FCC metal nanowires with lower fault energy such as Ni, Cu, Au and Ag under the same computational conditions. It is found that the elastic module of Al nanowire along different crystal orientations displays the relationship of E[111]>E[110]>E[100], which is generally true in other FCC nanowires. The yield stress of Al nanowire along different crystal orientations displays the relationship of σy[100]>σy[111]>σy[110], which is not generally true in other FCC nanowires. Furthermore, the deformation mechanism of Al nanowire along crystal orientations is clarified according to the evolution of microstructures. And it is compared with the nanowires of Ni, Cu, Au and Ag. It is also found that it difficult to predict the deformation mechanism accurately by the Schmid factor and the stacking fault energy for Al nanowire with high fault energy in such small scale.

Key words: Al nanowire, deformation mechanism, crystal orientations, molecular dynamics simulation