header

Large Scale 3-Dimensional Atomistic Simulations of Screw Dislocations Interacting with Coherent Twin Boundaries in Al, Cu and Ni Under Uniaxial and Multiaxial Loading Conditions

74 Pages Posted: 7 Jan 2019 First Look: Accepted

See all articles by Maxime Dupraz

Maxime Dupraz

Paul Scherrer Institute (PSI) - Photons for Engineering and Manufacturing Group

Satish I. Rao

Government of the United States of America - Materials Directorate; UES, Inc.

Helena Van Swygenhoven

Paul Scherrer Institute (PSI) - Photons for Engineering and Manufacturing Group; Ecole Polytechnique Fédérale de Lausanne - Neutrons and X-rays for Mechanics of Materials

Abstract

Large scale 3D atomistic simulations are performed to study the interaction between a curved dislocation with a dominant screw character and a Coherent Twin Boundary (CTB). Three FCC metals (Al, Cu and Ni) are addressed using 6 embedded-atom method (EAM) potentials. The reaction mechanisms are studied first under uniaxial stress showing that transmission mechanism and critical transmission stress depend on the material considered and differ from results reported in quasi- 2D simulations. Then, the influence of multiaxial stresses including shear components in the CTB is investigated. It is shown that the influence of the loading conditions, which can be represented in terms of the Escaig stress, is material dependent. In Al and Cu, the critical transmission stress is largely dependent on the Escaig stress while only mildly for Ni. The presence of a shear component in the CTB tends to increase the critical transmission stress for all three materials. The absorption and desorption mechanisms of the screw dislocation are correlated with a potential energy barrier.

Keywords: Molecular Dynamics, Twin boundary, Screw dislocation, Face-centered cubic crystals, Multiaxial loading

Suggested Citation

Dupraz, Maxime and Rao, Satish I. and Van Swygenhoven, Helena, Large Scale 3-Dimensional Atomistic Simulations of Screw Dislocations Interacting with Coherent Twin Boundaries in Al, Cu and Ni Under Uniaxial and Multiaxial Loading Conditions (January 4, 2019). Available at SSRN: https://ssrn.com/abstract=3310272 or http://dx.doi.org/10.2139/ssrn.3310272

Maxime Dupraz (Contact Author)

Paul Scherrer Institute (PSI) - Photons for Engineering and Manufacturing Group

5232 Villigen PSI
Switzerland

Satish I. Rao

Government of the United States of America - Materials Directorate

Dayton, OH 45432
United States

UES, Inc.

Beavercreek, OH 45432
United States

Helena Van Swygenhoven

Paul Scherrer Institute (PSI) - Photons for Engineering and Manufacturing Group ( email )

5232 Villigen PSI
Switzerland

Ecole Polytechnique Fédérale de Lausanne - Neutrons and X-rays for Mechanics of Materials ( email )

Station 5
Odyssea 1.04
1015 Lausanne, CH-1015
Switzerland

Here is the Coronavirus
related research on SSRN

Paper statistics

Abstract Views
244
Downloads
35