Heuristic Screening Database for the Development of High Entropy Alloys

The ability to rapidly and efficiently identify interesting high entropy alloys is of utmost importance in making optimal use of alloys in a wide range of modern technologies. High entropy alloys represent a massive, essentially infinite, alloy composition space to explore for a specific set of physical and mechanical properties. This thesis advances the study and application of HEAs by creating a heuristically-generated database of possible high entropy alloy systems, screening conceivable HEAs from the broader palette of multicomponent systems using several metrics proposed in the literature. This database enables researchers to quickly screen candidate alloy systems based on their potential to form a single-phase alloy, as well as their melting temperature, density, Youngs Modulus and several other properties, for further experimental and computational study. The resulting database includes over 84 million examined alloy combinations, which are evaluated using the heuristic models to arrive at a reduced set of candidate HEAs. For example, the model of Ye et al, with a critical ϕ value of 18, identifies over 310,529 candidate HEAs in 5-component systems of which there are 87,057 unique alloy systems. The value of such a database is the ability to quickly identify likely alloys that will form a single phase solid solution with the additional ability to further screen alloys based on a variety of physical properties. Using ϕ = 18 as the screening threshold eliminates 90% of the false positives, but will (however) miss 49% of the experimentally-observed HEAs (i.e., 49% false negatives)