Synthesis and Characterization of Pulsed Electrodeposited Cu-Y2O3 Coating

Abstract

In the present study electrodeposited Cu-Y2O3 composite coatings on copper substrate were synthesized from acidic copper sulfate bath with different concentrations (10 and 30g/l) of Y2O3 ultrafine particles using direct and pulsed direct current mode for better surface-mechanical and oxidation properties. The study was aimed for improvement of surface-mechanical and oxidation behavior of the intended coatings compared to pure copper with retention of considerable electrical conductivity for possible electrical applications. Phase/ morphology and elemental analysis of the coatings were carried out by XRD, SEM and EDS analysis. Surface-mechanical properties of deposited samples were studied systematically by microhardness and ball-on-plate type wear test. Thermal oxidation of the coating was also carried out. The coated samples’ electrical conductivity was analyzed by four probe technique. From the results, it was revealed that higher Y2O3 content in electrolyte tends to increase Y2O3 content in the deposits, which results in better hardness and wear resistance. Higher hardness and better wear resistance properties of co-deposited coatings were also attributed to finer matrix resulted by pulsing mode with higher pulse frequency. Better oxidation resistance was recorded in composite coatings due to better microstructure. Minor decrease in electrical conductivity of composite coatings was observed due to presence of Y2O3 and finer matrix, but values were in acceptable range. The present method can be considered useful to improve surface properties of electrically used copper components.