Design of corrosion-resistant high-entropy alloys through valence electron concentration and new PHACOMP

Journal article, 2021

Various methods can be used to predict the phase composition of conventional alloys. However, it is relatively difficult to predict high-entropy alloys (HEAs) owing to their complexity. There remain many challenges in designing HEAs with desirable properties. In this study, two strategies were applied to design corrosion-resistant non-equal-molar CoCrFeMoNi HEAs with a single phase. The two strategies were prediction for valence electron concentration dependent structural behavior to evaluate the matrix of HEAs, and average D-orbital energy level (M̅d) that was initially used to predict precipitation in superalloys under different temperatures. The validity of these two approaches was determined by thermal stability. The corrosion behaviors of the designed HEAs were investigated by polarization tests. In conclusion, the phase compositions of CoCrFeMoNi HEAs were predicted using a combination of the two approaches. The corrosion resistance was also competitive compared to that of Hastelloy C276. This research can provide a reference for the future development of corrosion-resistant HEAs with a single phase.