Properties of WC-Co coatings with Al₂O₃ addition

Properties of WC-Co coatings with Al₂O₃ addition on the C45 mild steel surface in acidic chloride solution were examined. The WC-Co-Al₂O₃ coatings on steel surfaces were deposited by an electro-spark (ESD) technique. The anti-corrosion properties of the coatings were mainly investigated by electrochemical methods. Moreover, the scanning electron microscope (SEM) was employed for the observation of the surface of materials. The structure of coatings depended on the composition of electrospark electrodes. In the WC80-Co5-Al₂O₃15 coating, the largest corrosion resistance was shown. The corrosion rate of the specimen was approximately eight times smaller than the coating without of Al₂O₃ addition. The aim of the research was to obtain, by adding alumina, an improvement in the functional properties of WC-Co coatings produced by the ESD method. Due to the original features of ESD coatings, they can be used in sliding friction pairs and as anti-wear coatings on cutting tools.