Two Level Investigation of Plasticity Driven Growth of Nanovoids Under High Rate Tension of Aluminum

With the help of molecular dynamics simulations the mechanism of nanovoid growth in aluminum under high rate tension is studied. We interpret the growth of nanovoids as the result of plastic deformation in zone close to void and corresponding atom rearrangement on void surface. The dependencies of critical negative pressure in systems of various atom number and void diameter at various temperatures are researched. It is shown,that critical pressure depends both on void diameter and simulated area size. Increase of temperature leads to linear decrease of system tensile strength. Also, some attention is givento the influence of initial stacking faults on critical pressure. The continuum model connectsthe void growth rate with the plastic flow around a void. The generation of dislocations near avoid surface is described with the Arrhenius type relation; the parameters of this relation arefitted by comparison with molecular dynamics data.