| About this Abstract |
| Meeting |
MS&T24: Materials Science & Technology
|
| Symposium
|
High Entropy Materials: Concentrated Solid Solutions, Intermetallics, Ceramics, Functional Materials and Beyond V
|
| Presentation Title |
Role of Temperature on Screw Dislocation Dynamics in Ta, Ta-W, and TaNbTi |
| Author(s) |
Pulkit Garg, Morgan R. Jones, Amy J. Clarke, Irene J. Beyerlein |
| On-Site Speaker (Planned) |
Pulkit Garg |
| Abstract Scope |
The mechanical properties of refractory multi-principal element alloys with body-centered cubic crystal structure exhibit a characteristic temperature dependence. In this work, we examine screw dislocation dynamics at different temperatures in Ta, Ta-W, and TaNbTi alloys using a three-dimensional, atomistic informed phase-field-dislocation dynamics model combined with Langevin dynamics. The critical stress for dislocation motion is observed to sharply decrease with increasing temperature, followed by a gradual decline and then a bend in the behavior, producing an athermal plateau above a critical temperature, similar to the three stages observed in the temperature-dependent yield strength of refractory alloys. The mechanism of dislocation motion is examined in three temperature regimes to understand the role of screw dislocations on the observed mechanical response of the selected refractory alloys. Overall, we show the screw dislocation motion, traditionally thought to be dominant at low temperatures, also significantly influences the high-temperature mechanical behavior of refractory metals and alloys. |