Surface-mechanical and oxidation behavior of electro-co-deposited Cu-Y2O3 composite coating

Electrodeposited Cu-Y2O3 composite coatings on copper substrate were synthesized from acidic copper sulfate bath with different concentrations (10 and 30 g/l) of Y2O3 ultrafine particles with direct current and pulsed direct current mode. Present study was aimed for better surface-mechanical and oxidation behavior of the coating compared to pure copper along with retaining considerable electrical conductivity for possible electrical applications. Phase, morphology and elemental analysis of the deposited coating were carried out by XRD, SEM and EDS techniques. The coatings reveal presence of Y2O3 with uniform distribution in a fine grained matrix. The surface mechanical properties of deposited samples were studied systematically by microhardness and ball-on-plate wear test. From the results it was observed that better hardness and wear resistance of the composite coating were greatly influenced by concentration of ultrafine Y2O3 particle and pulse parameters. Thermal oxidation behavior shows better oxidation resistance of Cu-Y2O3 composite coatings over pure copper. Electrical conductivity measurements show lower electrical conductivity of Cu-Y2O3 deposited sample compared to pure copper mainly due to finer matrix and second phase insulating particles, but values are in the acceptable range. The present coating can be considered as useful to improve surface properties of electrically used copper components.