制備及耐腐蝕性能
(1. 華南理工大學(xué) 機(jī)械與汽車工程學(xué)院，廣州 510640；
2. 華南理工大學(xué) 國(guó)家金屬材料近凈成形工程技術(shù)研究中心，廣州 510640)
摘 要: 采用微弧氧化技術(shù)和有機(jī)鍍膜技術(shù)相結(jié)合的復(fù)合處理方法實(shí)現(xiàn)Mg-Mn-Ce鎂合金表面改性，獲得超疏水復(fù)合膜層，研究微弧氧化膜的表面特征、有機(jī)鍍膜電化學(xué)反應(yīng)過(guò)程、復(fù)合膜層的潤(rùn)濕特性和耐腐蝕性能。結(jié)果表明：鎂合金經(jīng)微弧氧化處理后由于微弧氧化膜表面呈微納多孔結(jié)構(gòu)，表現(xiàn)為超親水特性，其蒸餾水的靜態(tài)接觸角接近0°；在微弧氧化膜上經(jīng)有機(jī)鍍膜后，其形成的有機(jī)薄膜的靜態(tài)接觸角高達(dá)173.3°，表現(xiàn)出優(yōu)良的超疏水特性。鎂合金經(jīng)微弧氧化處理后具有良好的耐腐蝕性能，經(jīng)有機(jī)鍍膜超疏水復(fù)合處理后，耐腐蝕性能得到進(jìn)一步提高。復(fù)合膜層在3.5% NaCl溶液中，與基體相比動(dòng)電位極化腐蝕電流密度減小了3個(gè)數(shù)量級(jí)、而電化學(xué)阻抗提高了3個(gè)數(shù)量級(jí)，耐腐蝕性能明顯改善。微弧氧化與有機(jī)鍍膜相結(jié)合的復(fù)合處理使鎂合金表面在實(shí)現(xiàn)超親水−超疏水功能轉(zhuǎn)換的同時(shí)顯著提高鎂合金的耐腐蝕性能。
關(guān)鍵字: Mg-Mn-Ce鎂合金；微弧氧化；有機(jī)鍍膜；超疏水；耐腐蝕性
（1. School of Mechanical and Automotive Engineering, South China University of Technology, Guangzhou 510640, China;
2. National Engineering Research Center of Near-Net-Shape Forming for Metallic Materials,
South China University of Technology, Guangzhou 510640, China）
Abstract:The super-hydrophobic duplex-treated film on the surface of Mg-Mn-Ce magnesium alloy was achieved by duplex treatment combined with techniques of micro-arc oxidation (MAO) and developed polymer plating, and its surface was modified. The surface characteristics of MAO film, electrochemical reaction process of polymer plating, wettability and corrosion behavior of duplex-treated film were investigated. The results show that the film treated by MAO on magnesium alloy surface becomes super-hydrophilic due to its micro and nano porous structure, and its static contact angle (CA) of distilled water is nearly 0°. After polymer plating on surface of MAO film with polymeric film, the character of super-hydrophobic is realized and behaves well with CA of 173.3°. The good property of corrosion resistance is obtained by MAO treatment, and the corrosion resistance is further improved after super-hydrophobic duplex treatment through polymer plating on the surface of MAO film. Compared to the corrosion resistance of bare magnesium alloy, the corrosion current density from potentiodynamic polarization measurement decreases by three orders of magnitude, and the electrochemical impedance from electrochemical impedance spectroscopy (EIS) increases by three orders of magnitude in 3.5% NaCl aqueous solution of duplex-treated film. Therefore, the duplex treatments by MAO and polymer plating on surface of the magnesium alloy are considered to realize functional transfer from super-hydrophilic to super-hydrophobic and improve its corrosion resistance greatly.
Key words: Mg-Mn-Ce magnesium alloy; micro-arc oxidation; polymer plating; super-hydrophobicity; corrosion resistance
