中國有色金屬學報(英文版)
Transactions of Nonferrous Metals Society of China
| Vol. 24 No. 4 April 2014 |
（1. Jiangsu Key Laboratory for Advanced Metallic Materials, School of Materials Science and Engineering,
Southeast University, Nanjing 211189, China;
2. Department of Physics and Materials Science, City University of Hong Kong,
Tat Chee, Avenue, Kowloon, Hong Kong, China）
Abstract:Magnesium alloy wires were processed by micro-arc oxidation (MAO) in a modified silicate-phosphate composite electrolyte containing hydroxyapatite (HA) nanopowders and NaOH. Effects of NaOH content in the composite electrolyte on the microstructure and properties of the MAO ceramic coatings on magnesium alloy wires were studied. It is found that the arc voltage of magnesium alloy wires in the micro-arc oxidation process is significantly reduced while the oxidation rate is accelerated. Addition of 2 g/L NaOH in the composite electrolyte is a better choice for improving corrosion resistance of magnesium alloy wires. During early simulated body fluids (SBF) immersion, the micro-arc oxidized magnesium alloy wires undergo a slow and stable degradation. After soaking for 28 d, the protective ceramic coating still shows no damage but significant degradation is observed for magnesium alloy wires after immersion for more than 60 d.
Key words: magnesium alloy wire; hydroxyapatite; micro-arc oxidation; corrosion resistance
