Influence of chemical composition on mechanical properties and energy absorption of CoNiFeCr high entropy alloys: A first-principles study

Metal matrix for the impact protection often requires high strength and good ductility as well as large energy absorption capacity. However, the traditional metal matrix alloys show relatively low strength and ductility to limit the energy absorption capacity. Here, the effect of chemical composition on properties of CoxNi50-xFe25Cr25 high entropy alloys is studied using first-principal calculations. The integrated method considering the competitive relationship between the strength and ductility is proposed to evaluate the energy absorption capacity. The results show that CoNiFeCr HEA with high strength and good ductility exhibits the exceptional energy absorption capacity, where the specific strength and ductility are 889 kN m/kg and 0.99. This work gives a new light into the selection and evaluation of strong energy-absorbing alloys. •Mechanical properties and energy absorption capacity of CoxNi50-xFe25Cr25 HEAs is studied by first-principal calculations.•An integrated method considering specific strength, VEC and twinnability is provided to evaluate energy absorption capacity.•Co element enhances strength, and Ni element improves ductility.•CoNiFeCr HEA with high strength and ductility exhibits exceptional energy absorption capacity.