Investigation of the electrochemical behaviour of WC–Co hardmetal with electrochemical and surface analytical methods

The corrosion behaviour of WC–Co based hardmetal was investigated in different solutions (acidic, neutral, and alkaline solutions) utilizing different electrochemical and surface analytical methods. At open-circuit potential WC–Co based hardmetals show rather high dissolution rates in all types of electrolyte. An efficient corrosion inhibitor (Benzotriazole, C6H5N3) could be found for a borate buffer solution, pH = 8.4. In situ STM allows to image the dissolution and redeposition of the cobalt phase in 1 M NaClO4. Confirmation of this result was obtained by XPS.