Friction Behavior of Brush Electro-plated Ni-PTFE Nano-composite Coating

Ni-PTFE nano-composite coatings were deposited on A3 carbon steel substrate using brush electro-plating technique.The morphologies of composite coatings as-etched after polishing were observed on a S-2700 scanning electron microscope(SEM).Hardness of composite coatings were investigated on a HX-1000 microhardness tester.Friction coefficient of composite coatings with different contents of PTFE under constant and various loads in a ball-on-disc configuration were measured on a MXTX S/X 20-0186 scratch tester.Roughness values were also measured on the same scratch tester.It was found that with addition of nano-PTFE,microstructure of coatings was refined and microhardness and roughness decreased.Friction coefficients of coatings,under condition of room temperature,low load and dry friction,also decreased with addition of nano-PTFE.Minimum friction coefficient could reach as low as 0.046.Values of friction coefficients of composite coatings and normal coatings increased with increase of loads.But friction coefficient values of the former were lower than that of the latter when loads were relatively low.