Hydroxyapatite Coating on Fluorine-treated Magnesium Alloy by Hydrothermal Method and Its Electrochemical Corrosion Behaviour in Hank’s Solution

详细

In order to improve the corrosion resistance and biocompatibility of magnesium alloys, hydroxyapatite (HA) coating with an outer chrysanthemum-like crystals layer and an inner needle-like crystals layer was successfully prepared on fluorine-treated AZ31 magnesium alloy by hydrothermal treatment. The needle-like crystals was about 1 μm long and grew almost vertically from fluoride conversion film. The inner layer arranged orderly and compactly, while the outer layer was thick but loose. The HA coating increased the open circuit potential, decreased the corrosion current density and improved the R_f and R_ct of fluoride coated sample, indicating that the HA coating can delay the degradation of fluoride conversion film and postpone the corrosion of AZ31 alloy in Hank’s solution.