Preparation of Superamphiphobic Surface on AZ31B Magnesium Alloy and Its Corrosion Resistance
Superamphiphobic surface films were successfully prepared on AZ31B Mg-alloy via etch-ing with HNO3 solution and afterwards modifying with PFDTES(1H,1H,2H,2H-perfluorodecyltriethoxysi-lane).The superamphiphobic surface film were characterized by means of scanning electron microscope(SEM),X-ray diffractometry(XRD),X-ray energy dispersive spectroscopy(EDS)and X-ray photoelectron spectrometer(XPS).The static contact angle(CA)was measured by optical contact angle meter to esti-mate their wettability,The electrochemical performance was evaluated in 3.5％NaCl aqueous solution by electrochemical work-station to estimate their corrosion resistance.Results show that the non-uniform dis-tribution of chemical composition of the Mg-alloy leads to different dissolution rates and degrees of the al-loy surface during the etching process,resulting in different morphology on surface.The special micro-structure formed on the etched alloy surface,combined with the modification of low surface energy mate-rials(PFDTES),enables the formation of a film with excellent liquid repellency on Mg-alloy.The contact angles(CAs)of water and ethylene glycol on the modified Mg-alloy surface were 159.3° and 155.2° re-spectively.In contrast to the bare Mg-alloy,the free corrosion potential of the superamphiphobic film cov-ered Mg-alloy shifted positively by 297 mV,and the corrosion current density decreases by more than 3 orders of magnitude,the charge transfer resistance increases by more than 2 orders of magnitude,in oth-er word,the anti-corrosion performance of the AZ31B Mg-alloy was well improved by the surface modifi-cation.Even after soaking in 3.5％NaCl solution for 72 h,the Mg-alloy with superamphiphobic film still maintains good corrosion resistance.
万方数据
维普
