Study on the Corrosion Behaviors of FeCrMnNiTi_xHigh Entropy Alloy in NaCl Solution

Abstract

Five metal nano powders of Fe, Cr, Mn, Ni and Ti were mixed by a planetary ball mill, and then three high entropy alloys of FeCrMnNiTi, FeCrMnNiTi0.5 and FeCrMnNi were prepared by vacuum casting technology. In order to investigate the corrosion behaviors of the three kinds of alloys in NaCl solution, the electrochemical workstation was used to measure the open circuit potential, polarization curve and AC impedance of the three alloys in 3.5%(mass fraction) NaCl solution. Furthermore, the microstructure of the corroded alloy was observed by using a metallurgical microscope and a scanning electron microscope. The electrochemical test results showed that when the self - corrosion potential of FeCrMnNiTi alloy was -0.301 V, the self - corrosion potential of FeCrMnNiTi0.5 alloy was -0.443 V. From the observation of corrosion product morphology, FeCrMnNiTi0.5 was dominated by grain boundary corrosion, and the other two alloys were dominated by pitting corrosion. Overall, FeCrMnNiTi had the best corrosion resistance and FeCrMnNiTi0.5 had the worst corrosion resistance. The addition of Ti might cause the alloy lattice distortion.

Keywords

• high entropy alloy|corrosion resistance|ti content|electrochemical properties