Preparation And Properties Of PTFE Modified Anti-corrosion Lubricating Coatings For Marine Equipment

The wear and corrosion of equipment in the marine environment is the biggest challenge facing marine development.The application of material tribology and improvement of service performance in seawater service environment,the efficient and feasible protection technology of grinding corrosion,which are important technical supports for the reliable operation of marine equipment.Hence,the research on polymer lubricating coatings with wear resistance and non-corrosibility was carried out in this study,which is of great significance for the protection of marine equipment moving parts.In this study,the polymer lubricating coatings with wear resistance and non-corrosibility based on poly-ether-ether-ketone（PEEK）and waterborne epoxy resin（EP）were developed by two preparation technology.On the one hand,the PTFE/graphite-reinforced PEEK-based composite coating was fabricated by electrodeposition method,and the effect of PTFE/graphite ratios on the mechanical and tribological properties of the PEEK coating was investigated.On the other hand,the nano-silicon reinforced epoxy coating,PTFE/nano-silicone reinforced epoxy coating and GO/PTFE/nano-silicon reinforced epoxy coating were fabricated by cold spraying method,and the effects of matrix and reinforced phases on the wear resistance and non-corrosibility of epoxy composite coating were characterized.The specific results are as follows:The wear resistance and lubrication performance of PEEK coatings were enhanced by co-modification of PTFE and graphite,and PTFE/graphite/PEEK composite electrodeposition coatings（PFG）were developed.The self-lubricating property,microhardness and wear resistance of the composite coating are significantly improved.The microhardness of the PFG1 composite coating（PTFE:graphite=1:3）is 21.64 HV_0.05,which is increased 41.07%compared with pure PEEK coating(15.34 HV_0.05).The average friction coefficient and erosion quotiety of PFG3 is0.08 and 1.61×10^-6 mm³/N·m at 10 N load and 5 Hz frequency,respectively.Which are reduced81.25%and 92.75%compared with pure PEEK coating(0.40 and 22.21×10^-6 mm³/N·m),respectively.Nano-organic silicon particles were in situ synthesized in EP by sol-gel method to improve the mechanical properties and wear resistance of EP coatings,thereby preparing nano-organic silicon reinforced epoxy resin composite coatings（ES）.The toughness of EP could be effectively improved by the flexible molecular chain of silicone,and the strength of EP could be enhanced by the high binding energy Si-O bond.When the nano-organosilicon content is 20%,the wear rate of ES20 coating is 3.40×10^-5 mm³/N m in atmospheric,which is reduced 99.36%compared with epoxy resin coating(533.2×10^-5 mm³/N·m)N m).When the nano-organosilicon content is 15%,the wear rate of ES15 coating is 1.70×10^-5 mm³/N m in the simulated seawater medium,which is decreased 79.52%compared with epoxy resin coating(8.3×10^-5 mm³/N m).ES15 has excellent corrosion resistance,and its coating can effectively hinder the spread of rust spots in the anti-corrosion test.The lubricating properties of ES15（nano-organosilicon content is 15%）were improved by PTFE,and the effect of PTFE/EP ratios on the friction properties of ES15 coatings was studied.The friction coefficient and wear rate of ESP0.8 coating are 0.09 and 9.40×10^-6 mm³/N·m respectively in the atmospheric when the ratio of PTFE/EP is 8:10.Which are reduced 88.00%and95.13%compared with ES15 coating(0.75 and 3.40×10^-5 mm³/N·m),respectively.Meanwhile,the friction coefficient and wear rate of ESP0.8 coating is 0.13 and 1.16×10^-5 mm³/N·m respectively in the simulated seawater medium.Which are decreased 50.00%and 31.76%compared with ES15 coating(0.26 and 1.70×10^-5 mm³/N·m).The friction performance of ESP0.8coating is stable at different sliding frequencies under dry friction conditions,the friction coefficient is about 0.10 and the wear rate is about 6.00×10^-6 mm³/N·m.In addition,ESP0.8exhibits excellent corrosion resistance,and the rust spots do not spread in the anti-corrosion test.The dispersion stability of graphene oxide（GO）in water was improved by polyacrylamide graft modification,and the GO/PTFE/silicon composites solid lubricant coating（ESPG）was prepared.The wear resistance of ESP0.8 coating（PTFE:EP=8:10）is effectively enhanced by the modified GO.The wear rate is only 1.90×10^-6 mm³/N·m when the content of GO is 0.05%,which is reduced 79.79%compared with ESP0.8 coating(9.40×10^-6 mm³/N·m)under dry friction conditions.The friction coefficient and wear rate of ESPG0.5 coating are 0.10 and 4.60×10^-6mm³/N m in the simulated seawater medium,respectively,which are reduced 23.08%and 60.34%respectively compared with ESPG0.8(0.13 and 11.6×10^-6 mm³/N m).ESPG0.3 coating exhibits excellent corrosion resistance,and the coating has no rust spots in the anti-corrosion test.