文摘
The present study explored the possibilities of improvement in the surface-mechanical properties of electrodeposited Cu-SiO2 composite coating and its underlying mechanism. Composite coatings were developed using SiO2-dispersed acidic copper sulfate electrolyte by direct current and pulse-current electro-codeposition techniques with variation of pulse frequencies at a fixed duty cycle. X-ray diffraction analysis of the coatings revealed information regarding the presence of various phases and crystallographic orientations of the deposited Cu matrix. Scanning electron microscopy and energy dispersive x-ray spectroscopy techniques were used to investigate the surface morphology and chemical composition of the coatings, respectively, and it was observed that SiO2 particles were uniformly distributed in the composite coatings. Surface roughness was found to be reduced with the increasing pulse frequency. The Vickers microhardness and ball-on-plate wear study showed improvement in surface-mechanical properties due to the formation of fine Cu matrix, dispersion strengthening due to homogeneously distributed SiO2 particles, and the preferred orientation of the Cu matrix. Marginal decrease in electrical conductivity with the increasing SiO2 content and pulse frequency was observed from the four-probe electrical conductivity measurement technique.