About this Abstract |
Meeting |
2021 TMS Annual Meeting & Exhibition
|
Symposium
|
High Entropy Alloys IX: Structures and Modeling
|
Presentation Title |
Monte Carlo Study of the Entropy Hypothesis Associated with High-entropy Alloys |
Author(s) |
Louis J. Santodonato, Peter K. Liaw |
On-Site Speaker (Planned) |
Peter K. Liaw |
Abstract Scope |
High-entropy alloy research is flourishing despite the considerable evidence against the underlying “entropy hypothesis”, which states that disordered solid-solution phases will tend to be stabilized, particularly in compositions with multiple elements in equimolar ratios, because of their high configurational entropy. This hypothesis is seemingly discredited because of the abundance of ordered phases and complex multiphase microstructures observed in room-temperature high-entropy alloys. The present Monte Carlo study, however, supports the validity of the entropy hypothesis, provided that we consider the stabilizing entropy effect acting on partially-ordered phases, derived from solid solutions. Using a model where the enthalpy is a function of the atomic configuration on a fixed lattice, we find that the configurational entropy of a high-temperature solid solution may evolve during cooling to produce a best-of-both-worlds atomic arrangement, such that a large enthalpy enhancement is obtained from a small entropy decrease. |
Proceedings Inclusion? |
Planned: TMS Journal: Metallurgical and Materials Transactions |
Keywords |
High-Entropy Alloys, Computational Materials Science & Engineering, Phase Transformations |