关键词: single crystal Al, molecular dynamics simulations, uniaxial compression, phase transition

Abstract: By molecular dynamics simulations employing an embedded atom method potential, we have investigated structural transformations in single crystal Al caused by uniaxial strain loading along the [001], [011] and [111] directions. We find that the structural transition is strongly dependent on the crystal orientations. The entire structure phase transition only occurs when loading along the [001] direction, and the increased amplitude of temperature for [001] loading is evidently lower than that for other orientations. The morphology evolutions of the structural transition for [011] and [111] loadings are analysed in detail. The results indicate that only 20% of atoms transit to the hcp phase for [011] and [111] loadings, and the appearance of the hcp phase is due to the partial dislocation moving forward on {111}_fcc family. For [011] loading, the hcp phase grows to form laminar morphology in four planes, which belong to the {111}_fcc family; while for [111] loading, the hcp phase grows into a laminar structure in three planes, which belong to the {111}_fcc family except for the (111) plane. In addition, the phase transition is evaluated by using the radial distribution functions.

Key words: single crystal Al, molecular dynamics simulations, uniaxial compression, phase transition