Preparation And Characterization Of Ni-SiC Nanocomposite Coating By Brush Plating

Brush plating technology is a branch of electrodeposition technology.It has been widely used in various industrial fields because of its simple operation,faster deposition rate and lower cost.In this paper,the technological parameters of Ni-SiC nano composite coating and the composition of bath were determined.The Ni-SiC nano composite coating was obtained by adding SiC particles in the brush plating bath.The influence of the concentration of nickel sulfate,the concentration of complexing agent,the pH value of bath solution,the working voltage and the relative speed of movement on the deposition rate,SiC content and microhardness of the coating were investigated.The surface morphology of Ni-SiC nanocomposite coating was observed by scanning electron microscope(SEM),and the composition of composite coating was detected and analyzed by means of EDS spectrometer supported by scanning electron microscope.The results show that the coating deposition rate,higher SiC particle composition and higher hardness can be obtained with proper technological conditions and proper chemical composition.The SEM analysis show that the surface morphology of the coatings with higher SiC particle content in composite compared to ordinary pure nickel coating surface is more smooth and compact structure,the coating crack number was significantly reduced,so that the SiC particles can significantly improve coating tightness,reduce the internal stress of coatings.Corrosion test results show that Ni-SiC nanocomposite coating has better corrosion resistance than pure nickel coating;The porosity test results show that the coating thickness affect the porosity,when the coating thickness reached 25 m,the gap of Ni-SiC composite coating rate reach 0,and when the coating thickness is 30 m,pure nickel coating porosity is 0,so that the Ni-SiC composite coating structure compared to pure nickel coating the more compact,better quality;The bonding strength of the coating shows that the bonding strength of pure nickel coating and Ni-SiC composite coating is good and almost the same;the friction and wear test results show that the friction with the passage of time,the wear volume of Ni-SiC nano composite coatings is obviously less than that of pure nickel coating,and SEM analysis of pure nickel coating delamination in after wear and Ni-SiC nano composite coating has no such phenomenon,also proved that the wear resistance of nano composite coatings is better than that of Ni-SiC pure nickel coating.When the oxidation temperature is between 600 and ~850 ?,the high-temperature oxidation resistance of Ni-SiC nanocomposite coating is better than that of pure nickel coating.