Wear behavior and corrosion properties of Fe-based thin film metallic glasses

Fe48Mo14Cr15Y2C15B6 (at%) thin film metallic glasses (TFMGs) with various thickness (125-745 nm) were deposited on glass and 304 stainless steel (SS) by using single-alloy target magnetron sputtering. X-ray diffraction and transmission electron microscopy verified the fully amorphous structure of the as-deposited films. Results of dry friction and wear tests against Si3N4 demonstrated that Fe-based TFMGs had lower friction coefficient and nearly three times higher wear resistance with respective to 304SS. The corrosion properties of the Fe-based TFMGs were evaluated in an artificial sweat solution by various electrochemical analytical techniques, including potentiodynamic, potentiostatic polarization and Mott-Schottky analysis. It was shown that the Fe-based TFMGs exhibited highly stable passivity and pitting resistance, which was significantly higher than that of uncoated 304SS. The good corrosion resistance of Fe-based TFMGs results from the lower defect density and higher thickness of the as-formed passive film as compared to 304SS. The pitting of the Fe-based TFMGs follows three distinct stages, i.e., pitting initiation, metastable pitting and stable pitting, as well as substrate dissolution-induced film rupture due to the adsorption and penetration of chloride ions in the artificial sweat solution. These findings are expected to broaden the application of Fe-based TFMGs as a highly protective film for electronic device applications.