| About this Abstract |
| Meeting |
2020 TMS Annual Meeting & Exhibition
|
| Symposium
|
Mechanical Response of Materials Investigated through Novel In-situ Experiments and Modeling
|
| Presentation Title |
Ab-initio Predictions of Plastic Anisotropy in BCC Metals |
| Author(s) |
Lucile Dezerald, Antoine Kraych, Emmanuel Clouet, Bassem Ben Yahia, Lisa Ventelon, Francois Willaime, David Rodney |
| On-Site Speaker (Planned) |
Lucile Dezerald |
| Abstract Scope |
Body-centered cubic (BCC) metals are known for their atypical plasticity at low temperatures. Here, we focus on their plastic anisotropy, also known as Schmid law deviation, which arises from ½<111> screw dislocation core effects. We use ab initio Density Functional Theory calculations to investigate the link between screw dislocation core properties and Schmid law deviation in BCC metals. We find that the dislocation trajectory systematically deviates from the average glide plane, leading to the well-known twinning/antitwinning asymmetry. Furthermore, we show that the dislocation core deformation modeled with eigenstrains is directly linked to the effect of non-glide stresses. We calculate with DFT the dislocation trajectory and eigenstrain in the absence of stress, and these values are used to predict Schmid law deviation in BCC metals. These results are validated by comparison with DFT calculations performed under shear and non-glide stresses, and our predictions are compared to the available experimental data. |
| Proceedings Inclusion? |
Planned: Supplemental Proceedings volume |