Preparation and properties of FHA coatings on micro-arc oxidised AZ91D magnesium alloy with different deposition times

ABSTRACT

To improve the corrosion resistance of magnesium (Mg) alloy under the physiological environment, fabrication of fluoridated hydroxyapatite (FHA) coating on micro-arc oxidised AZ91D Mg alloy was carried out by electrochemical deposition. The influence of electrochemical deposition time on surface morphology, phase composition, electrochemical properties, and degradation behaviour of the FHA coating was studied by SEM, XRD, electrochemical testing, and in-vitro immersion test, respectively. The results of the electrochemical test and in-vitro immersion test show that FHA coating can significantly improve corrosion resistance. In particular, the sample with deposition time of 60 min showed the minimum corrosion current density (1.26 × 10⁻⁶ A cm⁻²), which may be attributed to a significant decrease in the imperfections of the coating being achieved after this optimum deposition time.

KEYWORDS:

• Magnesium alloy
• micro-arc oxidation
• electrochemical deposition
• fluoridated hydroxyapatite
• deposition time
• corrosion resistance
• electrochemical test

Acknowledgements

This research did not receive any specific grant from funding agencies in the public, commercial, or not-for-profit sectors.

Disclosure statement

No potential conflict of interest was reported by the author(s).