The Effect of Aluminium Content on the Bioactivity Behaviour of Magnesium Alloys for Biomedical Applications

Abstract

AZ series alloy which consist of aluminium (Al) and zinc (Zn) with magnesium (Mg) as their base are the most investigated for biomedical applications among the Mg alloy. Al content plays a crucial part in differentiating the properties of Mg-based alloy for biomedical applications. Thus, this project picks up pure Mg and AZ31 (with 3% of Al) alloy and the effect of Al content has been investigated. In this study, Mg alloy has been fabricated via powder metallurgy method in order to investigate its bioactivity behaviour. Bioactivity test of pure Mg and AZ31 alloys were conducted by immersing the samples in simulated body fluid (SBF) solution up to 6 hours to observe the formation of apatite layer on the sample surface. The bioactivity behaviour of the samples has been observed using scanning electron microscope (SEM) and X-Ray Diffraction (XRD) analysis. After bioactivity test, sample AZ31 showed the formation of more apatite layers compared to sample of pure Mg with the existence of new phases which were Mg(OH)2 and MgO. This apatite layers might influence the ability of the Mg-based alloy to withstand the corrosive agent that will attack the alloy while being immersed in SBF.