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An attempt has been made to increase the corrosion resistance properties of medium steel substrate by using silica sol.The results show that: sol-gel method can increase corrosion resistance of phosphating coating. PS(silicon sol coated after phosphating )’s corrosion potential reduced more than P(phosphating sample)’s and its corrosion density also reduced.Polarizationg resistance of PS can improved many times.R2 of PS more reduced than P,but R3 improved more than ten times and R4 improved over sixty times by using equivalent circuit to fit EIS measurement. Corrosion resistance of PS was higher than that of P.

The properties of nano Al2O3modified electrolytic phosphating film have been studied through using the accelerated corrosion test, electrochemical testing techniques, scanning electron microscope (SEM) and X-ray diffraction (XRD) .The results show that, after adding nano- Al2O3 in electrolytic phosphating bath , morphology of phosphating film surface turned dense flake crystallization from needle crystal morphology of free-adding nano- Al2O3powder, and the value of impedance of the Al2O3incorporated phosphate coating was increased obviously.When the nano- Al2O3concentration was 15mg / L in electrolytic phosphating bath, the value of impedance of the coating is approximately two times larger than the phosphating coating directly formed on the low carbon steel.The corrosion resisting time of the coating was more than 420 s by CuSO4dripping test, and the corrosion current density of the phosphating sample was 1.164μA/cm2，in 3.5% NaCl solution, the corrosion inhibition efficiency reached 96.7%.

Ni-TiO2 nanocomposite coatings have been successfully fabricated via a route electrodeposition from nickel Watts bath containing nano-TiO2 particles, and characterized by scanning electron microscopy (SEM),X-ray diffraction(XRD), energy dispersive X-ray spectroscopy (EDS)and electrochemical techniques. The influence of preparation parameters on the properties of the coatings were investigated. The obtained results indicated that nano-TiO2 particles were distributed uniformly in the Ni matrix. It was found that the Ni-TiO2 nanocomposite coatings exhibited more excellent corrosion resistance and microhardness in comparison with pure nickel coating.

NiCrAlY coatings were deposited on CrNi3MoVA steel substrates by means of magnetron sputtering. The coatings were characterized in terms of their microstructure, hardness, friction coefficient, high-temperature oxidation resistance. Micro-indentation and tribometer testers were employed to measure the mechanical properties of NiCrAlY coatings and CrNi3MoVA steel. The results showed that the hardness of the coatings ranged from 5.7 to 5.9 GPa, with a higher value than that of CrNi3MoVA steel(4.1-4.3 GPa). The coefficient of steady-state friction of the coatings against 45-carbon-steel balls ranged from 0.35 to 0.40, with a lower value than that of CrNi3MoVA steel(0.63-0.68). The isothermal oxidation behavior at 850°C of the coatings were studied in comparison with CrNi3MoVA steel substrates. The results indicated that NiCrAlY coatings substantially increase the high-temperature oxidation resistance of CrNi3MoVA steel and the oxidation process was retarded mainly by the presence of outer complex oxide scales and a continuous Al2O3 inner layer on the coating.

Fluoralkylpolysiloxane modified Polyurethane (FSPU) films with high water contact angle (CA) were prepared. fluoralkylpolysiloxane was obtained using perfluoro octyl sulfuryl fluoride and terminal amino-silicone oil as reactants. Then, the isocyanate end capped PU prepolymer was synthesized by reacting isocyanate with a soft segment mixed by active amino-end-capping fluoralkylpolysiloxane and polyether glycol. The fluoralkylpolysiloxane modified PU films were obtained after the PU prepolymer was cured by 3,3 '- dichloro -4,4' – amino - diphenyl methane (MOCA). The results showed that the modified polyurethane with 10% (mass fraction) PFATPS had a good compatibility, low surface energy, surface water contact angle and surface oil contact angle was improved by 49° and 37° respectively, and heat resistance, water resistance was apparently improved.