Phase equilibria and corrosion behaviour of Fe-Co-Ni-Mn-Cr-V-Zr high entropy alloys : An experimental and simulation study

Abstract

The present study reports the design and development of multicomponent Fe35-yCo10Ni25Mn5Cr15V10Zry (y = 0, 2, 4, 6, 8, 10 at. %) high entropy alloys (HEAs) by integrated approach of combining thermodynamic simulation and experimental methods. The multicomponent HEAs are prepared by vacuum arc melting cum casting technique under the pure argon gas environment. The effect of Zr on microstructure evolution of Fe-Co-Ni-Mn-Cr-V HEAs is systematically investigated to understand the phase equilibria of designed HEAs using both thermodynamic simulation and the experimental results. The corrosion behaviour of Fe-Co-Ni-MnCr-V HEA is investigated using potentiodynamic polarization method, immersed in 3.5 wt. % NaCl electrolyte medium at room temperature and compared with the corrosion behaviour of conventional SS136 stainless steel, indicating that the corrosion resistance of designed HEA (corrosion rate = 0.0763 mmpy) is comparable with the conventional SS 316 steel (corrosion rate = 0.0527 mmpy). The experimental galvanic corrosion data as well as material data of FeCoNiMnCrV HEA was utilized to perform galvanic corrosion and crevice simulation by finite element model method using Comsol multiphysics software to understand the distribution of potential and current density in the electrolyte medium.