Dry electrochemical polishing of copper alloy in a medium containing ion-exchange resin

Abstract

Metal surfaces can be polished effectively and in an environmentally friendly way by virtue of the mechanical and electrochemical interaction between ion-exchange resin particles and the metal substrate. This paper studied this 'dry' polishing process and its property effects on 65 brass alloys. Surface morphology analysis revealed that the surface roughness can be reduced by over 71.5% from 0.764 ± 0.031 μm to 0.218 ± 0.080 μm with longer polishing time, and by over 67.1% from 0.764 ± 0.031 μm to 0.252 ± 0.02 μm with higher voltage. XPS and EDS results showed that only a small amount of oxygen species remained on the polished metal surface, while Cu and Zn were apparently present in the metallic state. The decrease in self-corrosion current indicated by the Tafel curves and the increase in the radius of the capacitive reactance circle contained in the Nyquist plots indicate that the surface corrosion resistance of the polished materials has been improved.