Interstitial loop strengthening upon deformation in aluminum via molecular dynamics simulations

The formation of prismatic interstitial loops during plastic deformation, as well as their interaction with dislocations, is systematically investigated in aluminum, using molecular dynamics simulations. First, direct dislocation interaction is responsible for producing various types of defects, typically vacancies and their clusters and interstitial loops. Secondly, small interstitial loops act as obstacles to dislocation gliding. When close to each other, a loop either decorates a dislocation with jogs or drags it elastically. The mobility of a dislocation decorated by a loop is significantly reduced. Depending on the relative position of the dislocation and the loop, the Peierls stress can increase several hundred times. The present work shows a complete picture of dislocation–loop interaction with atomic-scale details, which provides reliable information for parameterizing dislocation–debris interactions in constitutive models.