中国有色金属学报(英文版)
Transactions of Nonferrous Metals Society of China
Vol. 28 No. 11 November 2018 |
(1. Jiangsu Provincial Key Laboratory for Interventional Medical Devices, Huaiyin Institute of Technology, Huaian 223003, China;
2. School of Materials Science and Engineering, Nanchang Hangkong University, Nanchang 330063, China)
Abstract:In order to improve the corrosion resistance of the Mg alloys, the superhydrophobic coatings on AZ31 Mg alloy were prepared by a two-step process of micro-arc oxidation treatment and superhydrophobic treatment in stearic acid ethanol solution. The effects of voltages, frequencies and treatment time on the contact angle of the superhydrophobic treated sample were investigated. The results showed that with increasing the voltage, frequency and treatment time, all of the contact angles of the superhydrophobic treated sample increased first, and then decreased, reaching the maximum values at 350 V, 1000 Hz and 5 min, respectively. The optimal superhydrophobic coating was mainly composed of MgO and Mg2SiO4 phases, with the pore diameter of ~900 nm, the thickness of ~6.86 μm and the contact angle of 156.96°. The corrosion current density of the superhydrophobic AZ31 sample decreased by three orders of magnitude, and the amount of hydrogen evolution decreased by 94.77% compared with that of the AZ31 substrate sample.
Key words: superhydrophobic coating; AZ31 magnesium alloy; micro-arc oxidation; corrosion resistance; biomedical application