Microstructure, wear and corrosion properties of Cu-SiC/WCCo composite coatings on the Cu substrate surface by plasma spray method

Abstract

In this study, the microstructure, wear and corrosion properties of Cu–SiC/WCCo composite coatings produced on Cu substrates by plasma spray method were investigated. In order to achieve this aim, SiC and WCCo powders were added to copper at different rates such as 5 %, 10 % and 20 % by weight. In order to determine the microstructure properties and phase distribution of the produced coatings, optical microscope, SEM-EDS and XRD analysis were investigated. The reciprocating wear method was used in order to determine the wear properties and the potentiodynamic polarization and electrochemical impedance spectroscopy (EIS) methods was used to determine the corrosion properties. The electrical conductivities of the coating layers were performed according to the eddy current principle. XRD analysis results showed that in both coating types, ceramic particles decomposed in the plasma flame and as a result, binary and ternary metallographic phases were formed. There were significant increases in hardness by adding ceramic particles to Cu, especially with 20 % WCCo additive, the hardness obtained was 82 % higher than the Cu substrate. When the wear properties were examined, both abrasive/adhesive wear types were observed in the copper substrate and coating layers. In all samples, material loss increased as the load increased. Both EIS measurements and Tafel curve results showed that the Cu5% WCCo coating had the best corrosion resistance among the coatings. When the electrical conductivity results of all samples were compared, the electrical conductivity decreased with increasing rate of carbide in the coating.