The effect of Cr-content on the corrosion behavior of Ti0.5Mo0.5CoNiMnCrx high-entropy alloy thin films deposited by direct current magnetron sputtering

The present study aims to investigate the impact of Cr-content on the corrosion behavior of Ti0.5Mo0.5CoNiMnCrx high-entropy alloy thin films (HEATFs) fabricated through direct current magnetron sputtering. The microstructure and chemical composition of the HEATFs were characterized using grazing incidence X-ray diffraction (GIXRD), field emission scanning electron microscopy (FESEM), energy dispersive spectroscopy (EDS), and transmission electron microscopy (TEM). The corrosion performance of the HEATFs was evaluated through electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization tests in 1 M NaCl and 0.5 M H2SO4 solutions. The GIXRD, FESEM, and TEM results confirmed a uniform amorphous structure of the HEATFs. EIS analysis and assessment of fitted parameters indicated the formation of a protective passive film during immersion in 1 M NaCl at the open circuit potential (OCP), in contrast to the behavior observed in 0.5 M H2SO4. Moreover, all the HEATFs exhibited superior corrosion resistance compared to the 316 L stainless steel substrate, as evidenced by the potentiodynamic polarization curves obtained in both 1 M NaCl and 0.5 M H2SO4 environments.