Corrosion resistance of WC-Co-GO cemented carbides in NaCl solution

Abstract

WC-Co cemented carbide with deferent content (0, 0.1 wt% and 0.3 wt%) of graphene oxide (GO) were prepared by hot-pressing sintering. The effect of added GO on the corrosion resistance of WC-Co cemented carbide in sodium chloride solution was investigated by electrochemical method. With the increase of GO content, the grain size of WC shows a decreasing trend. The research findings suggested that the added GO increased remarkably the corrosion potential and decreased the corrosion current density in sodium chloride solution. As the GO content increased from 0 to 0.1 wt% and 0.3 wt%, the charge-change resistance (Rct) first increased from 6393 to 9201 Ω·cm2 and then decreased to 7842 Ω·cm2, correspondingly. The characterization of corrosion surface by SEM, EDS and XPS indicated that GO acted as the physical barrier and enabled WC-Co cemented carbide to have a larger ratio of the surface area of the anode phase to the cathode phase, which improved the corrosion resistance.