Preparation and Corrosion Resistance of Electrodeposited Hydroxyapatite Coating on Surface of AZ91 Magnesium Alloy

Hydroxyapatite (HA) coatings were prepared on the surface of AZ91 magnesium alloy by electrochemical deposition method.The effects of electrodeposition parameters on phase composition and morphology of the HA coatings were studied.And the corrosion resistance of the HA coatings was investigated by corrosion immersion testing and polarization curve testing.The results show that the HA coating prepared at pH value of 4.5 and temperature of 60℃ was the most compact,was composed of HA and presented radical structure with a thickness of about 60-70 μm.The HA coating had good protection for AZ91 magnesium alloy and significantly improved the alloy corrosion resistance of AZ91 magnesium alloy in physiological solution.