The Effect of Current Density on Friction and Wear Properties of Ni–W/PTFE Electro-Co-deposited Composite Coatings

This study reinforced Ni–W composites with polytetrafluoroethylene (PTFE) and deposited them on the low-carbon steel substrate by a pulse current (PC) electrodeposition technique. This resulted in improved abrasion resistance and low friction coefficient. The effect of current density on the co-depositions' surface morphology, nano-hardness, friction, and wear performances was investigated. Surface morphologies and worn surfaces of the produced composites were investigated by scanning electron microscopy (SEM). The phase structures of the deposited samples were analyzed using X-ray diffraction (XRD) by calculating the crystallite size and lattice strain. The results showed that PTFE could effectively enhance the tribological performances of the nickel matrix. It was shown that there was an increase in the current density and the same trend was also observed in the amount of incorporated PTFE into the matrix for a certain level. When the deposition was operated at the current density of 10 A/dm 2 , the average friction coefficient of the composite coating was reduced to 0.24. Moreover, the wear rate of the co-deposition obtained at 10 A/dm 2 was significantly decreased, and this was attributed to the uniform distribution of PTFE and refining microstructure of Ni–W.