The effect of current density on microstructural homogeneity, hardness, fracture toughness and electrochemical behavior of electrodeposited Cu-0.5Co/WC nano -composite coating

The Cu.-0.5Co/WC nano-composite coating was synthesized on CP-c pper substrate using Direct Current (D(7) electrodeposition method. In this work, it was tried to increase the hardness of surface without considerable degradation of copper's particular physical properties such as electrical conductivity. Tire effect of current density on microstructural homogeneity, hardness, fracture toughness, and electrochemical behavior of coating was investigated. The copper plates with the purity of 99.99% were used as electrodes. Tim electrolyte consists of tungsten carbide particles (30 g/l), copper sulfate (200 g/l), sulfuric acid (50 g/1), cobalt, sulfate (50 g/l), and Sodium Dodecyl Sulfate (SDS) (0.3 g/(g of WC)) as surfactant. The particle size of tungsten carbide powder was in the range of 40-70 nut. The distribution of tungsten carbide particles in coating was studied using FESEM. Aiicro-hardness measurement was performed in Vic:kers scale. Tire fracture toughness of coating was determined by bickers indentation test,. The corrosion resistance of the electrodeposited Cu-Co and Cu-Co/NATC nano-composite coatings was evaluated by polarization studies. Referring to the results, the use of optinium current density value.1A/cm(2)) during the electrodeposition process improves hardness and corrosion resistance of nano-composite coating. Additionally, Cu-Co/W(i composite coating shows more corrosion resistance than the itureinforced one. (C) 2017 Sharif University of Technology. All rights reserved.