Auger and Ellipsometric Investigation of the Oxidation Kinetics of Some Metallic Glasses

The oxidation kinetics of two metallic glasses have been studied by ellipsometry and Auger Electron spectroscopy. We have found that the presence of chromium in Fe based alloys has a marked influence on the thickness of corrosion film formed and on the kinetics of film formation. INTRODUCTION measured after various exposures to the high Several authors have reported that amorphous iron based alloys containing more than 8X chromium exhibit extremely high corrosion resistance in neutral and acid solutions ( I ) . The high corrosion resistance is in part related to the properties of the passive film formed, but mainly determined by the low defect density in the metallic glass surface. The medium and high temperature atmospheric oxidation of these amorphous alloys has never been studied, and it is the aim of the present investigation to see if the low defect density in temperature atmosphere. Since the high corrosion resistance of the chromium containing alloy has been attributed to the formation of the oxy-hydroxide we have also studied the corrosion kinetics in a moist atmosphere. After exposure for 3000 minutes the surface film of a representative selection of samples was studied by Auger electron spectroscopy. Concentration profiles of elements of interest were taken and the approximate composition determined from standard sensitivity factors. the amorphous state has any appreciable influence RESULTS on the rate and kinetics of atmospheric oxidation The thickness of the corrosion film uas