| About this Abstract |
| Meeting |
2021 TMS Annual Meeting & Exhibition
|
| Symposium
|
Phase Transformations and Microstructural Evolution
|
| Presentation Title |
About the Plasticity of Cobalt upon Phase Transformation: A High Temperature Nanoindentation Study |
| Author(s) |
Verena Maier-Kiener, Johann Kappacher, Helmut Clemens |
| On-Site Speaker (Planned) |
Verena Maier-Kiener |
| Abstract Scope |
The plastic deformation behavior of technically pure cobalt with a phase transformation temperature around 710K was investigated in the low temperature hexagonal closed packed and high temperature face centered cubic phase by means of high temperature nanoindentation techniques. Strain-rate jump tests were executed up to 873K to determine strain rate sensitivity, activation volume and activation energy of plastic deformation for identification of the rate-controlling deformation mechanism. From room temperature up to 473K the deformation behavior of the hexagonal phase was found to be controlled by dislocation segments overcoming the Peierls-Nabarro barrier to slip on the basal plane. Deformation twinning was apparent in the hexagonal phase, with rising activity as temperatures increase. The thermal activation of cross-slip leads to reduced twinning actions between 500K and 710K. In the high temperature cubic phase obstacle controlled dislocation glide was found to be the rate controlling mechanism and no deformation twinning was observed. |
| Proceedings Inclusion? |
Planned: |
| Keywords |
Mechanical Properties, Phase Transformations, High-Temperature Materials |