About this Abstract |
Meeting |
2021 TMS Annual Meeting & Exhibition
|
Symposium
|
High Entropy Alloys IX: Structures and Modeling
|
Presentation Title |
Statistics of the NiCoCr Medium-entropy Alloy: Novel Aspect of an Old Puzzle |
Author(s) |
Zongrui Pei, Rui Li, G. Malcolm Stocks, Michael C. Gao |
On-Site Speaker (Planned) |
Zongrui Pei |
Abstract Scope |
We study the K-state phenomenon in the NiCoCr medium-entropy alloy using first-principles techniques jointly with the efficient Wang-Landau Monte-Carlo and simulated annealing algorithms. Our theoretical results successfully explain the existence of the peak around 940 K in the experimental specific heat curve that characterizes the K-state phenomenon and give a fine picture of its atomic origin. The peak is caused by the maximum change of the local configurations characterized by the short-range order (SRO) parameters at that temperature. Surprisingly, we find the Ni-Co pair distribution is not random even above the ordering transition temperature, dramatically different from Ni-Cr and Co-Cr, indicating the system cannot be treated as a pseudo binary alloy. This prototypical example shows the complicated nature of multicomponent alloys different from binary alloys. Our methods can be directly used to study the important K-state phenomenon observed in many other composition-concentrated alloys regardless of their number of components. |
Proceedings Inclusion? |
Planned: TMS Journal: Metallurgical and Materials Transactions |
Keywords |
High-Entropy Alloys, Modeling and Simulation, Computational Materials Science & Engineering |