Abstract

AbstractThe aqueous oxidation of the cobalt allow Stellite‐6 has been studied in pH 10 water 285°C, as a function of dissolved oxygen concentration and length of exposure time. The result surface films were analysed by X‐ray photoelectron spectroscopy (XPS) and other techniques. Using XPS, a quantitative measurement of the oxide and metallic surface components was obtained and depth‐concentration profiles were determined. The effect of gaseous oxidation on the surface composition was also studied, and from a comparison of the oxidation behaviour under aqueous and gas phase conditions, solid state and solution‐transport processes could be distinguished. The gas phase studies showed that cobalt ions diffuse preferentially to the outer surface. During aqueous oxidation, however, the surface composition is found to be depleted in cobalt; preferential dissolution of the cobalt component of the alloy is therefore occurring under these aqueous conditions.

Full Text
Published version (Free)

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call