Abstract：Compact and uniform coatings were fabricated on LY12 aluminum alloy surface by adjusting process parameters and oxygen flow after micro-arc oxidation (MAO) treatment. The thickness, morphology, phase compositions and corrosion resistance were examined by SEM, XRD and electrochemical test system. The mechanism of MAO with oxygen was discussed, and the effect of oxygen flow on the coating compactness was analyzed. The results indicate that with the increase of time, voltage and concentration of electrolyte, the coating thickness changes regularly. The effect of oxygen on sintering can promote the growth of compact coatings, and the thickness of compact coatings first increases and then decreases with O2 rising. Under the conditions of 105g/L KF, 85g/L KOH, 12g/L NaAlO2, 110V for the voltage, 15min for treatment time and 0.010L/s for oxygen flow, a 30μm-thick compact coating can be formed on LY12 aluminum alloy. The corrosion potential of the coating increases to -0.11V, and the current density reduces to 2.1×10-6A/cm2, which is reduced by two orders of magnitude compared with the matrix and the corrosion resistance of the LY12 aluminum alloy significantly improves.
王玉洁, 张鹏, 王选, 杜云慧, 王胜林, 张伟一, 鹿红梅. 氧气流量对LY12铝合金微弧氧化膜致密性的影响[J]. 材料工程, 2019, 47(5): 86-92.
WANG Yu-jie, ZHANG Peng, WANG Xuan, DU Yun-hui, WANG Sheng-lin, ZHANG Wei-yi, LU Hong-mei. Effect of oxygen flow on compactness of micro-arc oxidation coatings on LY12 Al alloy. Journal of Materials Engineering, 2019, 47(5): 86-92.
 LIU Z G,MU Z T.Research on aircraft LY12CZ aluminum alloy corrosion damage prediction based on ARIMA model[J].Advanced Materials Research,2011,308/310:1016-1022.
 YANG Y,ZHOU L L.Improving corrosion resistance of friction stir welding joint of 7075 aluminum alloy by micro-arc oxidation[J].Journal of Materials Science & Technology,2014,30(12):1251-1254.
 YANG W,JIANG B L,WANG A Y,et al.Effect of negatively charged ions on the formation of microarc oxidation coating on 2024 aluminium alloy[J].Journal of Materials Science & Technology,2012,28(8):707-712.
 吴振东,李超楠,夏琦兴,等.电解液体系对镁合金热控涂层结构和性能的影响[J].硅酸盐学报,2015,43(12):1731-1736. WU Z D,LI C N,XIA Q X,et al.Influence of different electrolyte systems on structure and property of thermal control coatings on Mg alloy[J].Journal of the Chinese Ceramic Society,2015,43(12):1731-1736.
 SHEN D J,LI G L,GUO C H,et al.Microstructure and corrosion behavior of micro-arc oxidation coating on 6061 aluminum alloy pre-treated by high-temperature oxidation[J].Applied Surface Science,2013,287(24):451-456.
 李淑华,沈大为,祖媛媛,等.2A06铝合金表面微弧氧化陶瓷层摩擦学特性[J].稀有金属材料与工程,2014,43(1):154-157. LI S H,SHEN D W,ZU Y Y,et al.Tribological performance of ceramic composite coatings obtained by microarc oxidation on 2A06 aluminum alloy[J].Rare Metal Materials and Engineering,2014,43(1):154-157.
 GUO Q Q,JIANG B L,LI J P,et al.Corrosion resistance of mi-cro-arc oxidized ceramic coating on cast hypereutectic alloy[J].Transactions of Nonferrous Metals Society of China,2010,20(11):2204-2207.
 WEI T B,YAN F Y,TIAN J.Characterization and wear-and cor-rosion-resistance of microarc oxidation ceramic coatings on aluminum alloy[J].Journal of Alloys & Compounds,2005,389(1):169-176.
 SONG Y W,DONG K H,SHAN D Y,et al.Investigation of a no-vel self-sealing pore micro-arc oxidation film on AM60 magnesium alloy[J].Journal of Magnesium and Alloys,2013,1(1):82-87.
 CUI W F,JIN L,ZHOU L.Surface characteristics and electro-chemical corrosion behavior of a pre-anodized microarc oxidation coating on titanium alloy[J].Mater Sci Eng C Mater Biol Appl,2013,33(7):3775-3779.
 WU P N,XI J J, ZHAO J,et al.Preparation of compact micro-arc oxidation coatings on aluminum alloys[J].Applied Mechanics & Materials,2010,33(16):492-495.
 TANG M Q,LI W P,LIU H C,et al.Influence of K2TiF6 in electrolyte on characteristics of the microarc oxidation coating on aluminum alloy[J].Current Applied Physics,2012,12(5):1259-1265.
 魏方红,李慕勤,郭小娟,等.植酸对纯镁超声微弧氧化层防护性能的影响[J].中国表面工程,2015,28(2):78-83. WEI F H,LI M Q,GUO X J,et al.Effect of phytic acid on protective performance of film formed on pure magnesium by ultrasonic micro-arc oxidation[J].China Surface Engineering,2015,28(2):78-83.
 喻杰,韦东波,王岩,等.激光重熔改性铝合金微弧氧化膜层的组织与性能[J].无机材料学报,2013,28(8):859-863. YU J,WEI D B,WANG Y,et al.Structure and property of micro-arc oxidation coating modified by laser melting and solid-ifying on aluminum alloy[J].Journal of Inorganic Materials,2013,28(8):859-863.
 杜云慧,张鹏,刘汉武.一种AZ91镁合金表面厚保护层处理方法:201110101512.3[P].2011-09-14. DU Y H,ZHANG P,LIU H W.Protective layer treatment of AZ91 magnesium alloy surface:201110101512.3[P].2011-09-14.
 LIU Y J,XU J Y,GAO Y,et al.Influences of additive on the formation and corrosion resistance of micro-arc oxidation ceramic coatings on aluminum alloy[J].Physics Procedia,2012,32:107-112.
 SIMCHEN F,SIEBER M,LAMPKE T.Electrolyte influence on ignition of plasma electrolytic oxidation processes on light metals[J].Surface & Coatings Technology,2017,315:205-213.
 杨威,赵玉峰,杨世彦.微弧氧化电源特性和参数对膜层性能及电能消耗的影响[J].材料工程,2010(2):86-90. YANG W,ZHAO Y F,YANG S Y.Effects of characteristic and parameters of power supply on micro-arc oxidation coatings prop-erty and energy consumption[J].Journal of Materials Engin-eering,2010(2):86-90.
 郭洪飞,安茂忠,徐莘,等.镁合金微弧氧化工艺条件对陶瓷膜耐蚀性的影响[J].材料工程,2006(3):29-32. GUO H F,AN M Z,XU S,et al.Effect of operating condition on corrosion resistance of ceramic coatings formed on magnesium alloys by micro-arc oxidation[J].Journal of Materials Engin-eering,2006(3):29-32.
 NECHAEV G G,POPOVA S S.Dynamic model of single disc-harge during microarc oxidation[J].Theoretical Foundations of Chemical Engineering,2015,49(4):447-452.
 BOSTA M M S A,MA K J,CHIEN H H.Effect of anodic current density on characteristics and low temperature IR emissivity of ceramic coating on aluminum 6061 alloy prepared by microarc oxidation[J].Journal of Ceramics,2013(2):1-14.
 WANG L,CHEN L,YAN Z C,et al.Optical emission spectros-copy studies of discharge mechanism and plasma characteristics during plasma electrolytic oxidation of magnesium in different electrolytes[J].Surface & Coatings Technology,2010,205(6):1651-1658.
 McPHERSON R.Formation of metastable phases in flame-and plasma-prepared alumina[J].Journal of Materials Science,1973,8(6):851-858.
 LEVIN I,BRANDON D.Metastable alumina polymorphs:crys-tal structures and transition sequences[J].Journal of the Amer-ican Ceramic Society,1998,81(8):1995-2012.
 薛文彬,邓志威,来永春,等.铝合金微弧氧化陶瓷膜的相分布及其形成[J].材料研究学报,1997,11(2):169-172. XUE W B,DENG Z W,LAI Y C,et al.Phase distribution and formation mechanism of ceramic coatings formed by microarc oxidation(MAO) on Al alloy[J].Chinese Journal of Materials Research,1997,11(2):169-172.
 BAGWELLl R B,MESSING G L.Effect of seeding and water vapor on the nucleation and growth of α-Al2O3 from γ-Al2O3[J].Journal of the American Ceramic Society,1999,82(4):825-832.
 蔡俊.富Al端Al-Cr合金低温热氧化制备α-Al2O3研究[D].杭州:浙江大学,2013. CAI J.Preparation of α-Al2O3 at low temperature by thermal ox-idation of Al-rich Al-Cr alloy[D].Hangzhou:Zhejiang Univers-ity,2013.