Effect of tribo-layer on the corrosion behavior of WC-Co and WC-Ni cemented carbides in synthetic mine water

For rock drilling applications, the cemented carbides containing hard WC grains in a ductile Co binder are commonly used as drill buttons. In considering environmental and health aspects an alternate to Co-binder is pursued. present work, using standard scratch testing friction wear properties of WC-20 vol% Ni grade studied compared that grade. The deformation characteristics carbide grades evaluated correlated microstructural changes during testing. Also, electrochemical impedance spectroscopy (EIS) behavior as-polished scratch-tested was at open circuit potential condition simulated mine water (SMW) for 1 h. obtained polarization resistance charge transfer values from EIS analysis corrosion samples. both conditions WC-Ni exhibited higher indicating high than WC-Co. comparison sample, activity particular within scratch-induced tribo-layer. Severe complete removal tribo-layer observed WC-Co when exposed SMW 15 Site-specific scanning electron microscope (SEM) energy-dispersive X-ray (EDX) were carried out get insight into carbides.