Preparation And Corrosion Resistance Of Magnesium Alloys Superhydrophobic Fillm Layer

Aiming at the loose surface of magnesium alloy micro-arc oxidation film layer,the corrosion resistance can not meet the requirements of practical use.In this study,the electrolyte modification method is used to make the nano-silica particles in the electrolyte enter the magnesium alloy micro-arc oxidation film layer.The surface pore size is reduced to the micro-nano scale,the film density is improved,the requirements of the preparation of the super-hydrophobic film layer are satisfied,and the magnesium alloy micro-preparation is prepared by self-assembly reaction of stearic acid and noctyltriethoxysilane on the surface thereof.Arc oxidation superhydrophobic composite film layer.XRD,SEM,EDS,FTIR,electrochemical polarization and impedance spectroscopy and water contact angle test were used to study the phase composition,morphology,chemical composition and corrosion resistance of different nano-SiO2 coatings on the magnesium oxide coating.The effects of properties,compactness and wettability optimize the surface morphology of the optimal magnesium oxide film required for the preparation of composite superhydrophobic film.The self-assembly time of nano-SiO2 in micro-arc oxidation electrolyte and the self-assembly time of stearic acid and n-octyltriethoxysilane were discussed.The contact angle,surface morphology and corrosion resistance of magnesium oxide superhydrophobic composite film were discussed.The law of influence of performance.The results show that 6g/L nano-SiO2 particles were added in the process of micro-arc oxidation,and then modified into 40%of stearic acid ethanol + nano-SiO2+noctyltriethoxysilane solution.The wettability of the hydrophobic film layer is the largest,compared with 81.3° of the magnesium matrix and 39.50°of the magnesium alloy MAO film layer.The wettability of the magnesium alloy superhydrophobic film layer can reach 156.2°,and the rolling angle is 8.8°.Electrochemical tests on the super-hydrophobic film of magnesium alloy showed that when the nano-Si02 particles were added in an amount of 6g/L and the self-assembly time was 40h,the self-corrosion current was 3.744E-11 A/cm2 and the self-corrosion potential was 0.38V.Compared with the corrosion current of 16h,the corrosion current is reduced by 3 orders of magnitude,and the self-corrosion potential is increased by 0.58V.At the same time,the impedance value of the superhydrophobic film layer obtained after immersion for 40h reaches the maximum value of 2.707*107?·cm²,which is the impedance value at 16h.474 times,so the corrosion resistance of the obtained magnesium alloy superhydrophobic sample was modified in stearic acid ethanol+nano sio₂+noctyltriethoxysilane solution,self-assembly time was 40h,and the addition amount was 6g/L.significantly enhanced.