Enhanced strength of (CoFeNiMn)100−xCrx (x = 5, 20, 35 at.%) high entropy alloys via formation of carbide phases produced from industrial-grade raw materials

(CoFeNiMn)100−xCrx (x = 5, 20, 35 at.%) HEAs were produced using vacuum arc melting followed by suction casting using industrial-grade raw materials and subsequent annealing at 1150 °C for 24 h. The increasing Cr content triggered the formation of the Cr7C3 in the FCC matrix due to the presence of C impurity in the raw materials. The increasing Cr content from 5 to 35 at.% raised the hardness from 206 (±7) to 383 (±4) HV and yield strength from 210 to 350 MPa due to the embedded Cr7C3 phases in the matrix. The HEA consists of 20 at.% Cr was found to be the most promising alloy due to the strength-ductility trade-off with the values of 350 MPa compressive yield strength and 10.7 % strain. The enhanced mechanical properties of the HEAs by using industrial-grade low-cost raw materials could make them more attractive materials for industrial applications.