Investigation of Wear Properties and Corrosion Resistance of Electrodeposited Ni-P-PTFE Nanocomposite Coating on Mg-Li alloy

Abstract

Ni-P-polytetrafluorethylene nanocomposite coatings based on Mg-Li alloy were successfully prepared by utilizing electrodeposition method. The nanocomposite coatings were investigated employing scanning electron microscopy, atomic force microscopy, and X-ray diffraction. The microstructure and composition of the coating were studied by friction, wear and corrosion tests. The experimental results reveal that when the concentration of PTFE is 3 g / L, deposition temperature is 70 °C, current density is 2 A/dm2, and pH of the plating solution is approximately 5.5, a uniform and dense Ni-P-PTFE nanocomposite coating is formed on Magnesium alloy substrate, and it exhibited a low coefficient of friction (∼1.5) and superior abrasion resistance. The co-deposition of PTFE particles can effectively reduce the friction coefficient and wear rate, and the wear mechanism is characteristic cutting wear. Under artificial seawater conditions, the experiments have demonstrated that the nanocomposite material possesses a corrosion current density of 3.9×10-5 A/cm2.