Fabrication Of Superhydrophobic Surface On Aluminum Substrates And Its Research Of Durability

Due to its special properties,such as self-cleaning,antifouling,anti-friction and corrosion resistance,superhydrophobic surfaces are widely used in textile,buildings,aircraft,medical and other fields.However,the application of superhydrophobic surfaces were limited by many practical problems such as complex process,high cost,easy to fall off and poor durability of environment.In order to prepare stable and durable surfaces with simple process and low cost,two methods were used to fabricate bionic superhydrophobic surfaces on aluminum substrates.The component,microstructure and wettability of superhydrophobic surfaces were characterized by means of X-ray diffraction(XRD),scanning electron microscope(SEM)and contact angle measurement.Tribological properties were investigated by UMT under 0.5N load with steel ball,mechanical durability was investigated by UMT under 0.1N load with metallographic polishing cloth.The corrosion resistance of super-hydrophobic samples against acid,alkali and salt were investigated by CHI660 E electrochemical workstation.The main contents of this paper are listed as follows:(1)ZnO films with nanostructure were prepared on aluminum substrates by hydrothermal method.After heating 20 h,the surface turned into superhydrophobic with a static contact angle of 152° and rolling angle of 2°.Friction test showed that superhydrophobic film reduced the friction coefficient of aluminum surface from 0.7 to 0.5.Mechanical hydrophobic durability test showed that the substrates still remained hydrophobic property after 2400 wear cycles.Electrochemical impedance spectroscopy and Potentiodynamic polarization curves showed that the corrosion rate of aluminum surface with superhydrophobic surface decreased dramatically,the inhibition rate can be reached 93.7%?94.8%?93.8% respectively.The as-prepared coating also showed good stability in the corrosive solution with PH value of 1-14,repeated UV irradiation and exposed long-term in air.(2)Micro-nanostructure on aluminum surface was configurated via chemical etching.After heating 20 h,the etched aluminum surface exhibited superhydrophobic properties with a static contact angle of 150° and rolling angle of 5°.Friction and wear test showed that the friction coefficient of the substrates remained 0.6 under constant loading of 0.5N,and the surface still remained high static contact angle after 2400 wear cycles under constant loading of 0.1N.Electrochemical test showed that as-prepared surface can provide effective anticorrosion ability against acid,alkali and salt.The inhibition rate can reached 84.9%?55.4%?62.8% respectively.The surface also showed good stability in corrosive solution with PH value of 1-14 and exposed long-term in air.In this paper,We prepared superhydrophobic surface on aluminum substrate by using different surface fabrication techniques,which have not only good mechanical durability,but also excellent anti-corrosion resistance and stability.This superhydrophobic surface may widen the applications of Al and its alloys in various industrial fields.