About this Abstract |
Meeting |
2023 TMS Annual Meeting & Exhibition
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Symposium
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Local Ordering in Materials and Its Impacts on Mechanical Behaviors, Radiation Damage, and Corrosion
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Presentation Title |
Dislocation Motions in Refractory High-entropy Alloys and Effects of Chemical Order and Disorder |
Author(s) |
Xinyi Wang, Francesco Maresca, Penghui Cao |
On-Site Speaker (Planned) |
Xinyi Wang |
Abstract Scope |
The origin of extraordinary mechanical properties in body-centered cubic refractory high entropy alloys (HEAs) can be traced back to dislocation motion in concentrated solid solutions because the locally high chemical fluctuations in HEAs inevitably influence its motion mechanisms. In this talk, we will present the atomistic mechanisms and the associated energy barriers governing screw and edge dislocation motion in bcc refractory HEAs using a set of atomistic simulation techniques. The screw dislocation migration pathway reveals a hierarchical and multilevel structure potential energy landscape with a collection of small basins nested in large metabasin. By introducing chemical short-range order (SRO), the energy barriers for individual mechanisms all increase but to different extents. Finally, we will discuss the effect of SRO on edge dislocation migration barrier, and our preliminary results indicate a possible SRO-strengthening to softening crossover, depending on temperature and strain rate. |
Proceedings Inclusion? |
Planned: |