Title: Understanding 112 Slip in Tantalum
Presenter: Jonathan Zimmerman
Affiliation: Sandia National Laboratories
Abstract: Screw dislocations of bcc tantalum have been investigated with molecular dynamics simulations. Understanding slip in bcc metals is challenging, as slip may occur on a variety of different planes, and the critical stress for slip on a given plane does not adhere to Schmid’s law. Results from multiple interatomic potentials reveal that at zero temperature, the dislocation core splits prior to, or in conjunction with, apparent slip on 112 planes. This behavior is found to be dependent on the applied stress state, resulting in discontinuities in the measured critical resolved shear stress. Additional simulations that focus on the effect of temperature and kink formation make it possible to identify fundamental traits necessary for inclusion in plasticity models.
Sandia is a multi-program laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed-Martin Corporation, for the United States Department of Energy’s National Nuclear Security Administration under contract DE-AC04-94AL85000.