About this Abstract |
Meeting |
2022 TMS Annual Meeting & Exhibition
|
Symposium
|
Advances in Multi-Principal Elements Alloys X: Structures and Modeling
|
Presentation Title |
Dislocation Motions in Refractory Multi-principal Alloys and Effects of Chemical Order and Disorder |
Author(s) |
Xinyi Wang, Francesco Maresca, Penghui Cao |
On-Site Speaker (Planned) |
Xinyi Wang |
Abstract Scope |
Body-centered cubic (bcc) refractory multi-principal alloys (r-MPAs) have been the subject of extensive research over the last few years because of their high strength and weak temperature dependence. The origin of extraordinary mechanical properties can be traced back to dislocation motion in concentrated solid solutions. Here, we couple a set of atomistic simulation techniques to investigate the atomistic mechanisms and the associated energy barriers governing screw dislocation motion in bcc r-MPAs. The detailed analysis shows that the screw dislocation reveals a hierarchical and multilevel structure potential energy landscape (PEL) with a collection of small basins nested in large metabasin. This striking feature pertaining to r-MPAs exerts a trapping force and back stress on saddle point activations, retarding dislocation movement. By introducing chemical short-range order, the energy barriers for individual mechanisms all increase but to different extents, leading to the dominant mechanism drift from kink-glide to kink-pair nucleation. |
Proceedings Inclusion? |
Planned: TMS Journal: Metallurgical and Materials Transactions |
Keywords |
High-Entropy Alloys, Modeling and Simulation, Mechanical Properties |