Modified nanostructured hydroxyapatite coating to control the degradation of magnesium alloy AZ31 in simulated body fluid

This research covers a different microstructural and electrochemical investigation on hydroxyapatite (HAP) coatings deposited on AZ31 magnesium alloy. Microstructure characterization and functional group identification were performed using X-ray diffraction (XRD), Fourier transform infrared and scanning electron microscopy (SEM) techniques. The prepared samples were immersed in simulated body fluid to study the degradation behavior of AZ31 and the amount of hydrogen produced. Electrochemical techniques were employed to evaluate and compare the corrosion behavior of the nano-HAP (n-HAP) coated and uncoated samples. The changes in pH value during the corrosion process were also measured. Results suggest the noticeable capability of n-HAP coatings to stabilize the alkalization behavior and to improve the corrosion resistance of AZ31 alloy. Consequently, the hydrogen evolution process beneath the n-HAP coating decreased significantly. It was concluded that an n-HAP coated AZ31 alloy could be a good candidate as a type of biodegradable implant material for biomedical applications. (C) 2014 Elsevier B.V. All rights reserved.