Effects of CH3OH Addition on Plasma Electrolytic Oxidation of AZ31 Magnesium Alloys*supported by National Natural Science Foundation of China (No. 21376088), the Project of Production, Education and Research, Guangdong Province and Ministry of Education (Nos. 2012B09100063, 2012A090300015), and Guangzhou Science and Technology Plan Projects of China (No. 2014Y2-00042). (September 2015)

• Record Type: Journal Article
• Authors: He, Yongyi; Chen, Li; Yan, Zongcheng; Zhang, Yalei
• Is Part Of: Plasma science and technology. Volume 17:Number 9(2015:Sep.)
• Page Start: 761
• Page End: 766
• Publication Date: 2015-09
• Subjects: Plasma (Ionized gases) -- Periodicals; 530.44
• DOI: 10.1088/1009-0630/17/9/07
• Languages: English
• ISSNs: 1009-0630

Abstract

<abstract> <title>Abstract</title> <p>Plasma electrolytic oxidation (PEO) films on AZ31 magnesium alloys were prepared in alkaline silicate electrolytes (base electrolyte) with the addition of different volume concentrations of CH₃OH, which was used to adjust the thickness of the vapor sheath. The compositions, morphologies, and thicknesses of ceramic layers formed with different CH₃OH concentrations were determined via X-ray diffraction (XRD), energy-dispersive spectroscopy (EDS), and scanning electron microscopy (SEM). Corrosion behavior of the oxide films was evaluated in 3.5 wt.% NaCl solution using potentiodynamic polarization tests. PEO coatings mainly comprised Mg, MgO, and Mg₂SiO₄. The addition of CH₃OH in base electrolytes affected the thickness, pores diameter, and Mg₂SiO₄ content in the films. The films formed in the electrolyte containing 12% CH₃OH exhibited the highest thickness. The coatings formed in the electrolyte containing different concentrations of CH₃OH exhibited similar corrosion resistance. The energy consumption of PEO markedly decreased upon the addition of CH₃OH to the electrolytes. The result is helpful for energy saving in the PEO process.</p> </abstract>