Understanding the Effect of Tungsten on Corrosion Behavior of AlCuCrFeMnWx High-Entropy Alloys in 3.5 wt.% NaCl Solution

The electrochemical study of AlCuCrFeMnW x ( x = 0, 0.05, 0.1, 0.5, 1 mol) high-entropy alloys (HEA) is performed in 3.5 wt.% NaCl solution at room temperature (25 °C). The potentiodynamic polarization curve of the AlCuCrFeMnW x ( x = 0, 0.05, 0.1, 0.5, 1 mol) alloys obtained in 3.5 wt.% NaCl solution shows that the corrosion resistance of the tungsten (W)-free HEA is lower than the alloys containing W. It is observed that W forms solid WO 3 layer in the outer region of the film in a 3.5 wt.% NaCl. The scanning electron microscopy and infrared spectroscopy confirmed the electrochemical results. The electrochemical impedance spectroscopy of these alloys had one capacitive loop, which represented the presence of electrical double layer.