TCHEA: A thermodynamic database for the development of high entropy alloys

High entropy alloys (HEAs), as a new class of materials, have been receiving great scientific and engineering interests in the last decades. The CALPHAD (calculation of phase diagrams) approach, which has for over 30 years been widely employed in alloy design, is one of the most promising methods for exploring potential HEAs. In this presentation we report a specialized thermodynamic database TCHEA (version 2) for the exploration of HEAs within the framework of the following 20 elements: Al-Co-Cr-Cu-Fe-Hf-Mn-Mo-Nb-Ni-Re-Ru-Ta-Ti-V-W-Zr-C-N-Si. Using TCHEA2, one can reasonably predict the phase stability with respect to temperature and composition for the desired multicomponent solid solutions, such as BCC, FCC and/or HCP. It is also possible to evaluate the competition between ordered phases such as B2 and L12, intermetallic compounds, and all other solid solutions. The database has been validated against most reported HEAs available in the literature with excellent agreement between the thermodynamic calculations (e.g. predicting phase relations, equilibrium and accumulated fractions and major constituents) and experimental observations (e.g. micro-structures, phase identifications and fractions).