Effect of Complex Agents on the Performance of Electrodeposited Ni-Graphite Composites

Abstract

Ni-graphite composites were prepared using co-electrodeposited technique in sulfamate bath. To obtain an optimum combination of nickel and graphite in the composites with excellent performance such as wear resistance, corrosion resistance and microhardness and so on, effects of complex agents on the performances of composites were investigated in this work. The obtained Ni-graphite coatings were characterized by means of SEM, EDS and the microhardness measurement, it was revealed that Ni-graphite coating exhibit fine-grained structure with uniform surface and high microhardness values, although some pores and defects were still present in the coating. In addition, the co-electrodeposited Ni-12.16vol% graphite coatings showed considerably better performance, analysis of Tafel curves demonstrated that corrosion resistance of the coating prepared from bath containing complex agents were better than those prepared from bath without complex agents in the NaCl and HCl solution, but worse in the NaOH solution.