Influence of laser power on the corrosive resistance of WC-Cu coating

Influence of laser power on the corrosive resistance of WC-Cu electrospark deposition (ESD) coatings on the C45 carbon steel surface in acidic chloride solution was examined. Potentiodynamic polarization technique was used. Scanning electron microscope (SEM) was employed for the observation the surface of materials. The structure of coatings was dependent on the composition of electrospark electrodes. The WC25-Cu75 coating the largest corrosion resistance was showed. The laser treatment of 70 W laser power caused the homogenization of the structure, and the healing of microcracks and pores of ESD coatings. After laser irradiation a decrease of the microhardness of WC25-Cu75 coating was observed. The corrosion rate of sample for the laser treatment of WC25-Cu75 coating was approximately one-fifth that of coating without laser irradiation.