Computationally-driven engineering of sublattice ordering in a hexagonal AlHfScTiZr high entropy alloy

Computationally-driven engineering of sublattice ordering in a hexagonal AlHfScTiZr high entropy alloy

Rogal, Lukasz (Polish Academy of Sciences)
Bobrowski, Piotr (Polish Academy of Sciences)
Körmann, F.H.W. (TU Delft (OLD) MSE-7)
Divinski, Sergiy (University of Münster)
Stein, Frank (Max-Planck-Institut für Eisenforschung)
Grabowski, Blazej (Max-Planck-Institut für Eisenforschung)

2017

Multi-principle element alloys have enormous potential, but their exploration suffers from the tremendously large range of configurations. In the last decade such alloys have been designed with a focus on random solid solutions. Here we apply an experimentally verified, combined thermodynamic and first-principles design strategy to reverse the traditional approach and to generate a new type of hcp Al-Hf-Sc-Ti-Zr high entropy alloy with a hitherto unique structure. A phase diagram analysis narrows down the large compositional space to a well-defined set of candidates. First-principles calculations demonstrate the energetic preference of an ordered superstructure over the competing disordered solid solutions. The chief ingredient is the Al concentration, which can be tuned to achieve a D0₁₉ ordering on the hexagonal lattice. The computationally designed D0₁₉ superstructure is experimentally confirmed by transmission electron microscopy and X-ray studies. Our scheme enables the exploration of a new class of high entropy alloys.

Atomistic models
Design, synthesis and processing
Metals and alloys

http://resolver.tudelft.nl/uuid:f082a2e0-27a6-4d8b-b53a-6ee7f6e64491

https://doi.org/10.1038/s41598-017-02385-w

2045-2322

Scientific Reports, 7

Institutional Repository

journal article

© 2017 Lukasz Rogal, Piotr Bobrowski, F.H.W. Körmann, Sergiy Divinski, Frank Stein, Blazej Grabowski