Preliminary study of hydroxyapatite particles air abrasive blasting on Mg-4Zn-0.3Ca surface

Currently, Mg based alloys are one group of promising candidates for biodegradable bone implant applications. However, their high rate degradation in human body environment is an obstacle and should be treated or coated. In this study Mg–4Zn–0.3Ca alloy surfaces are blasted with bioactive hydroxyapatite (HA) fine particle in order to enhance their corrosion resistance and biocompatibility. Characterization of the sample surfaces was focused on the microstructure and topography changes. Series of analysis were conducted such as phases analysis using X-ray diffraction (XRD), microstructure using scanning electron microscopy (SEM) and electrochemical measurements. The results revealed that the HA particles air abrasive blasting irregularly and roughly shaped the Mg–4Zn–0.3Ca alloy surfaces with small portion of HA particles impregnation. XRD result shows the presence of Mg matrix, secondary phase of Ca2Mg6Zn3 and embedded HA phases on the roughened surface. The HA blasted sample indicates better corrosion resistance in SBF solution compared to the non-blasted samples. This has proven that the HA particles air abrasive blasting is responsible for improving the alloy corrosion resistance. Therefore, by roughening the alloy surface with more uniform HA particles, corrosion resistance could be possibly increased.