| About this Abstract |
| Meeting |
2020 TMS Annual Meeting & Exhibition
|
| Symposium
|
Mechanical Behavior at the Nanoscale V
|
| Presentation Title |
On the Estimation of Thermal Activation Parameters for Portevin-Le Chatelier Effect from Nanoindentation Data |
| Author(s) |
Henry Ovri, Erica T Lilleodden |
| On-Site Speaker (Planned) |
Henry Ovri |
| Abstract Scope |
Since Portevin-Le Chaterlier (PLC) effect is driven by thermally activated mechanisms, it is of interest to determine the associated activation enthalpy, ∆Ea. This parameter is important for understanding the underlying deformation mechanisms and identifying the relevant atomic species that diffuse to the dislocations during deformation. Currently, most of the available models for estimating ∆Ea are based on the critical strain, εc, for the onset of the phenomenon during uniaxial tests. However, a εc is not always observed and some of the models incorporate unverified dislocation density and vacancy concentration dependences. In view of this, we present a nanoindentation-based approach that obviates the need for εc and gives estimates of ∆Ea, along with the associated activation volume and attempt frequency. The estimated parameters are in good agreement with reported values for the Al-Mg alloy studied herein. The results also reveal the utility of the technique for investigations of PLC more generally. |
| Proceedings Inclusion? |
Planned: Supplemental Proceedings volume |