Effect of Precipitated Particles on Corrosion Behavior of VCrFeTa0.1W0.1 and VCrFeTa0.2W0.2 Refractory High-Entropy Alloys

In this study, the influence of precipitated Laves particles on the metastable pitting of VCrFeTa0.1W0.1 and VCrFeTa0.2W0.2 refractory high-entropy alloys (HEAs) in 3.5 wt.% NaCl solution was investigated. Microstructures and corrosion behaviors were characterized by XRD, SEM, TEM, potentiodynamic polarization (PDP), electrochemical impedance spectroscopy (EIS), and X-ray photoelectron spectroscopy (XPS), and the underlying mechanisms were elucidated. The PDP test results demonstrate that the precipitated Laves particles reduce the pitting resistance of HEAs. The corrosion current densities of VCrFeTa0.1W0.1 and VCrFeTa0.2W0.2 HEAs are 0.066 and 1.361 μA/cm2, respectively, and the pitting potentials are 1.058 and 0.881 V, respectively; that is, reducing the Laves-particle content lowers the corrosion current density by a factor of approximately 20 and raises the pitting potential by approximately 180 mV. The corrosion current density and pitting potential of VCrFeTa0.1W0.1 are competitive with those of reported HEAs and traditional alloys.