2017/02/14 by Łukasz Rogal, Lukasz Rogal, Rogal, Lukasz +11
Engineering · Physics and Astronomy · #Additive Manufacturing Materials and Processes #FOS: Physical sciences #High Entropy Alloys Studies #High-Temperature Coating Behaviors #Materials Science (cond-mat.mtrl-sci) #cond-mat.mtrl-sci
paper · pdf · doi:10.48550/arxiv.1702.04038
arxiv created 2017/02/14 · openalex publication_date 2017/02/14 · arxiv updated 2017/02/15 · openalex created_date 2019/06/27 · openalex updated_date 2026/07/28
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 of 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.