Comparing modeling predictions of aluminum edge dislocations: semidiscrete variational Peierls- Nabarro versus atomistics

Abstract

Multiple computational methods for modeling dislocations are implemented into a high-throughput calculation framework allowing for rigorous investigations comparing the methodologies. Focusing on aluminum edge dislocations, over twenty classical aluminum interatomic potentials are used to directly model dislocation structures using molecular dynamics, as well as provide input data for solving the semidiscrete variational Peierls-Nabarro dislocation model. The most important material parameter for determining the dislocation’s predicted shape is the intrinsic stacking fault energy, and both methods show similar trends across all potentials. Additionally, tests are done to vigorously determine if a recent correction to the Peierls- Nabarro model results in better agreement with the atomistic calculations.