Corrosion resistant body-centered cubic VNbTa refractory medium-entropy alloy

The corrosion behavior of VNbTa medium-entropy alloy (MEA) was investigated by electrochemical measurement and first-principles calculation. Due to the synergism of higher bond strength and higher oxygen or OH adsorption heat among constituent elements, the MEA has better corrosion resistance than 316 L stainless steel. The stability passive film was related to the high -valent oxides (V2O5, Nb2O5, and Ta2O5). The calculation results show that VNbTa MEA has a high work function and adsorption energy for O, and the formation of initial passive film is mainly determined by the bonding of surface Ta, V atoms and O atoms.