Remarkable cavitation erosion–corrosion resistance of CoCrFeNiTiMo high-entropy alloy coatings

A CoCrFeNiTiMo high entropy alloy (HEA) coating was prepared onto a Ti-6Al-4 V substrate using the double cathode glow discharge method. This innovative HEA coating exhibited a duplex phase microstructure, composed of a BCC-structure solid solution phase and a tetragonal structured intermetallic phase, Co2Mo3, and possessed high hardness, high load bearing capacity and strong adhesion to the substrate. The HEA coating underwent much less severe cavitation erosion damage in a 3.5 % NaCl solution relative to Ti-6Al-4 V according to the results of electrochemical measurements and the cumulative weight loss, because of its unique combination of excellent mechanical properties and high corrosion resistance.