Abstract
In order to improve the corrosion resistance of Co-Cr-Mo alloy, a hybrid process combining ELID (Electrolytic in-process dressing) grinding with thermal oxidation (TO) was performed and then the treated surfaces were observed and analyzed using a scanning electron microscope (SEM), a glow discharge optical emission spectrometer (GD-OES) and an X-ray photoelectron spectroscope (XPS). In order to evaluate corrosion resistance, potentiodynamic polarization measurement and metallic ion elution tests were carried out. The color of the treated surfaces changed and the levels of oxygen content increased significantly due to the thermal oxidation treatment. In particular, specimens treated with ELID/TO hybrid processing showed the thicker oxide layers than those of the P/TO hybrid processed ones. In addition, the amount of cobalt on the surface diminished by ELID/TO hybrid processing. Specimens treated with the ELID/TO hybrid processing showed a lower amount of cobalt ion elution among all specimens. These results suggest that it is possible to apply a ELID/TO hybrid process as a surface finishing method for metal implants and improve their corrosion resistance by applying an ELID/TO hybrid process.
