Simple Approach to Model the Strength of Solid-Solution High Entropy Alloys in Co-Cr-Fe-Mn-Ni System

simple fitting approach is introduced for modeling the strength (hardness) of quaternary and quinary face-centered cubic (fcc) solid solution high entropy alloys (HEAs) in the Co-Cr-Fe-Mn-Ni system. The strength of solid solution HEAs could be modeled by a polynomial equation where experimental data are used to find the polynomial coefficients. It is observed that the proposed polynomial could model the strength of solid solution HEAs very well. Effects of constituent elements on the hardness of quinary Co-Cr-Fe-Mn-Ni alloys are investigated; the results indicate that alloys’ strength decreases with the Fe content. The softening effect of Fe is explained by considering its impact on reducing the shear modulus of alloys. Furthermore, the effects of parameters enthalpy of mixing and valence electron concentration on the strength of HEAs are investigated. The results show that the enthalpy of mixing has a noticeable impact on the hardness of quinary Co-Cr-Fe-Mn-Ni alloys, and the strength increases with decreasing the enthalpy of mixing. Furthermore, the results show that quinary Co-Cr-Fe-Mn-Ni alloys’ hardness increases with the parameter valence electron concentration.