Void growth by dislocation adsorption

IMPACT STATEMENT Void growth during ductile rupture is mediated by dislocation adsorption, not dislocation emission as previously theorized. The mechanism is consistent with Rice-Tracey scaling and observations of voids near cell walls. We propose a dislocation adsorption-based mechanism for void growth in metals, wherein a void grows as dislocations from the bulk annihilate at its surface. The basic process is governed by glide and cross-slip of dislocations at the surface of a void. Using molecular dynamics simulations we show that when dislocations are present around a void, growth occurs more quickly and at much lower stresses than when the crystal is initially dislocation-free. Finally, we show that adsorption-mediated growth predicts an exponential dependence on the hydrostatic stress, consistent with the well-known Rice-Tracey equation.