No abstract

Zn–Ni and Zn–Ni/PTFE coatings were produced by the electrodeposition technique. The effect of PTFE particles concentration on co-deposition of these particles was investigated. Morphology of Zn–Ni and Zn–Ni/PTFE coatings along with their corrosion and tribological behavior were studied. The results showed that maximum incorporation of PTFE particles was obtained in the presence of 30 g l−1 of these particles in the bath. Clusters of cauliflower-like morphology of Zn–Ni film became coarser by the incorporation of PTFE particles. Potentiodynamic polarization and electrochemical impedance spectroscopy results revealed that Zn-14Ni film had the best corrosion resistance between all the samples. The corrosion resistance of the alloy film was decreased by the incorporation of PTFE particles. However, Zn–Ni/PTFE film had higher corrosion resistance than the steel substrate. According to hardness and wear results, while Zn-14Ni film had the highest hardness between all the samples, Zn–Ni/PTFE film had the lowest volume loss and friction coefficient.

In this research, Zn-Ni and Zn-Ni/PTFE coatings were electrodeposited from sulfate-based electrolytes. Potentiodynamic polarization and electrochemical impedance spectroscopy (EIS) techniques were used to investigate the corrosion properties of the coatings. Hardness and tribological behavior of the coatings were examined by the Vickers microhardness testing machine and the pin-on-disc method, respectively. Chemical composition and morphology of the as-deposited and worn surfaces of the coatings were studied by a scanning electron microscope (SEM) equipped with an energy dispersive X-ray spectrometer (EDS). According to the results, the corrosion current density of the Zn-Ni film was about 30% of that of the composite coating. Hardness of the alloy film was partially decreased by the incorporation of Polytetrafluoroethylene (PTFE) particles. However, the wear loss and coefficient of friction of the Zn-Ni/PTFE coating were, respectively, about 43% and 57% of those of the Zn-Ni film. Moreover, wear mechanism was changed from plastic deformation and adhesive wear to slight abrasion by the co-deposition of PTFE particles.