Plasticity at the Atomic Scale: Parametric, Atomistic, and Electronic Structure Methods

Abstract

Over the last hundred years our evolving comprehension of deformation has been based on the discovery and understanding of the line defects (dislocations) that control plasticity. While our ability to directly model various defects has improved over this time, a great deal has been learned about deformation processes using parametric approaches. A natural extension of analytic models, parametric studies are sometimes overlooked in our search for the most accurate computational representation of the mechanism that controls a given materials property. However, parametric strategies has been broadly employed in the materials community. For example, we have used parametric approaches to study the influence of micro-structural properties on the strengthening mechanisms in model Ni-based super alloys and the influence of chemistry on high temperature strengthening in Ti-Al alloys [1, 2]. Also, current dislocation dynamics calculations can be viewed as a template for parametric studies of the role of various defect-defect interactions and how they control macroscopic behavior. The deformation behavior of the bcc transition metals provides an excellent historical example of this type of work and how it influenced our understanding of these materials.