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. (C) 2004 Elsevier B.V. All rights reserved.