Mechanical properties of aluminum through electronic- and atomic-scale simulations

Abstract

Implementing the integrated computational materials engineering methodology in modeling plastic deformation processes and associated phenomena can provide a unique opportunity for a deeper study of material behavior at smaller scales and result in more precise and accurate predictions. This study presents a multiscale modeling framework linking two different length scales – namely, the electronic and the atomic scale – to investigate the mechanical properties of pure aluminum (Al) and to achieve the required parameters and information for higher scales. At the electronic scale, the elastic properties and interfacial energies for aluminum were garnered from density functional theory simulations to calibrate the modified embedded atom method (MEAM) potentials required for atomic simulations. The calculation for the generalized stacking fault energy resulted in an intrinsic stacking fault energy of 185.5 mJ/m2. Using the parameter calculated at the electronic scale as well as the MEAM potential parameters, the edge dislocation mobility of aluminum from molecular dynamics simulations was calculated at the atomic scale (nano). A drag coefficient of 7.3 × 10−5 Pa s was computed at 300 K. The dependency of the drag coefficient on the temperature was also studied, and the results showed that the velocity linearly depended on τ/T up to 0.4 MPa/K.