The magnesium–aluminium connecting parts are important application form for lightweight structural materials. But the conductive connect of magnesium and aluminium will cause serious galvanic corrosion problems. Therefore, the overall corrosion protective treatment is necessary. A ceramic coating was prepared via overall micro-arc oxidation to wrap the magnesium–aluminium connecting part integrally. The surface morphologies and compositions of the coatings were analysed by scanning electron microscopy and X-ray energy dispersive spectroscopy. The corrosion behaviour of the coatings was investigated with potentiodynamic polarisation tests in 3.5 wt-% NaCl solution. The growth process of ceramic coating on aluminium and magnesium surface was investigated, which showed the micro-arc oxidation reaction priority and the balanced growth process of ceramic coating under unbalanced micro-arc distribution. The results demonstrated that the overall micro-arc oxidation treatment improved the corrosion resistance and reduced the corrosion potential difference of each metal of magnesium–aluminium connecting part.
Tan SGChen QZLi SB. Research progress of micro-arc oxidation on metal composite. Surf Technol. 2016; 11: 004.
2.
ShuaiGMaSNQiuJ. Research progress in micro-arc oxidation on aluminum alloy welding zone. Spec Cast Nonferr Alloys. 2015; 35 (7): 709–713.
3.
YangSZhouLChengX.Micro-arc oxide film of aluminum coating pre-sprayed on AZ31 magnesium alloy. Magnes Technol. 2016; 291–295. doi:10.1002/9781119274803.
4.
WangSZChenLZZhaoY.Study on galvanic behaviors of TA2 titanium alloy & 5083 aluminum alloys and connection technology. J Jiangsu Univ Sci Technol. 2012; 26 (02): 133–136.
5.
SongZXieZYuG. A novel palladium-free surface activation process for electroless nickel deposition on micro-arc oxidation film of AZ91D Mg alloy. J Alloys Compd. 2015; 623: 274–281. doi: 10.1016/j.jallcom.2014.10.130
6.
DongKSongYShanD. Corrosion behavior of a self-sealing pore micro-arc oxidation film on AM60 magnesium alloy. Corros Sci. 2015; 100: 275–283. doi: 10.1016/j.corsci.2015.08.004
7.
GuoH.The electrochemical corrosion behavior and mechanism of microarc oxidation coatings on magnesium alloys. Lanzhou: Lanzhou University of Technology; 2014.
8.
PingWJianpingLIYongchunGUO. Growth process and corrosion resistance of ceramic coatings of micro-arc oxidation on Mg-Gd-Y magnesium alloys. J Rare Earths. 2010; 28 (5): 798–802. doi: 10.1016/S1002-0721(09)60204-0
9.
WangSLiuP.The technology of preparing green coating by conducting micro-arc oxidation on AZ91D magnesium alloy. Pol J Chem Technol. 2016; 18 (4): 36–40. doi: 10.1515/pjct-2016-0068
10.
DurduSUstaM.Characterization and mechanical properties of coatings on magnesium by micro arc oxidation. Appl Surf Sci. 2012; 261: 774–782. doi: 10.1016/j.apsusc.2012.08.099
11.
PingWLiuDLiJ. Growth process and corrosion resistance of micro-arc oxidation coating on Mg-Zn-Gd magnesium alloys. T Nonferr Metal Soc. 2010; 20 (11): 2198–2203. doi: 10.1016/S1003-6326(09)60442-8
12.
TangHGaoY.Preparation and characterization of hydroxyapatite containing coating on AZ31 magnesium alloy by micro-arc oxidation. J Alloys Compd. 2016; 688: 699–708. doi: 10.1016/j.jallcom.2016.07.079
13.
HuiJZ.The study of ceramic on aluminum-magnesium alloy surface treated by micro-arc oxidation under different electrical parameters. Xi'an: Chang'an University; 2006.
14.
XueWBChenYFLiYL. Surface protection of friction stir welding joint for AZ31 magnesium alloy coated by micro-arc oxidation. J Mater Eng. 2012; 0 (12): 1–6.
15.
YangYZhouL.Improving corrosion resistance of friction stir welding joint of 7075 aluminum alloy by micro-arc oxidation. J Mater Sci Technol. 2014; 30 (12): 1251–1254. doi: 10.1016/j.jmst.2014.07.017
16.
LalehMKargarFRouhaghdamAS.Investigation of rare earth sealing of porous micro-arc oxidation coating formed on AZ91D magnesium alloy. J Rare Earths. 2012; 30 (12): 1293–1297. doi: 10.1016/S1002-0721(12)60223-3
17.
LuLXueWBJinXB. The electrochemical corrosion behavior of friction stir welding joint of 5083 aluminum alloy by micro-arc oxidation. Rare Met Mater Eng.2012; 41 (9): 1597–1601.
18.
LuoZHaoZJiangB. Micro arc oxidation and electrophoretic deposition effect on damping and sound transmission characteristics of AZ31B magnesium alloy. J Cent South Univ. 2014; 21 (9): 3419–3425. doi: 10.1007/s11771-014-2317-5
19.
TangHGaoY.Preparation and characterization of hydroxyapatite containing coating on AZ31 magnesium alloy by micro-arc oxidation. J Alloys Compd. 2016; 688: 699–708. doi: 10.1016/j.jallcom.2016.07.079
20.
TangHYuDLuoY. Preparation and characterization of HA microflowers coating on AZ31 magnesium alloy by micro-arc oxidation and a solution treatment. Appl Surf Sci. 2013; 264: 816–822. doi: 10.1016/j.apsusc.2012.10.146
21.
TangHHanYWuT. Synthesis and properties of hydroxyapatite-containing coating on AZ31 magnesium alloy by micro-arc oxidation. Appl Surf Sci. 2017; 400: 391–404. doi: 10.1016/j.apsusc.2016.12.216
22.
CuiXLinXLiuC. Fabrication and corrosion resistance of a hydrophobic micro-arc oxidation coating on AZ31 Mg alloy. Corros Sci. 2015; 90: 402–412. doi: 10.1016/j.corsci.2014.10.041
23.
CuiXYangRLiuC. Structure and corrosion resistance of modified micro-arc oxidation coating on AZ31B magnesium alloy. Trans Nonferr Met Soc China. 2016; 26 (3): 814–821. doi: 10.1016/S1003-6326(16)64172-9
24.
KrishnaLRPoshalGJyothirmayiA. Relative hardness and corrosion behavior of micro arc oxidation coatings deposited on binary and ternary magnesium alloys. Mater Des. 2015; 77: 6–14. doi: 10.1016/j.matdes.2015.04.006
25.
KhannaRKokuboTMatsushitaT. Novel artificial hip joint: a layer of alumina on Ti–6Al–4 V alloy formed by micro-arc oxidation. Mater Sci Eng C. 2015; 55: 393–400. doi: 10.1016/j.msec.2015.05.021
26.
CuiLYGaoSDLiPP. Corrosion resistance of a self-healing micro-arc oxidation/polymethyltrimethoxysilane composite coating on magnesium alloy AZ31. Corros Sci. 2017; 118: 84–95. doi: 10.1016/j.corsci.2017.01.025
