The influence of helium bubble on the elastic properties of aluminum

Abstract

The elastic properties of helium-bubble embedded aluminum have been investigated by molecular dynamics simulation. First, the interaction potentials between aluminum and helium atoms are parametrized with the help of first-principle method. Secondly, we studied the influence of helium bubble on the elastic properties of aluminum from the following two aspects: the size of helium bubble (the diameters being 16, 20, 25, 30 and 3.5nm, respectively) and the internal pressure of helium bubble (the ratios of the number of helium atoms to the vacancies being about 5%, 15%, 45% and 85%, respectively). The results show that the elastic constants c11, c12 and c44 decrease with increasing diameter of helium bubble, however, for a fixed size they are almost independent of the internal pressure of helium bubble. Using the elastic composite system model, the influence of the size and internal pressure of helium bubble on aluminum is explained qualitatively based on the analytical results and is consistent with our calculated results.