Mg-1Sn/Al2O3 biodegradable composites: effect of Al2O3 addition on mechanical, in-vitro corrosion and bioactivity response

Abstract

The present work investigates the mechanical, corrosion and bioactive behaviour of Mg-1Sn reinforced with 5, 10 and 15 wt% of Al2O3 fabricated by squeeze casting route. The phase analysis and microstructure of as-cast composites were characterized by x-ray diffraction (XRD) and scanning electron microscope (SEM) coupled with energy dispersive spectroscopy (EDS) respectively. Mechanical properties were evaluated by conducting the compression test. In order to evaluate the in-vitro corrosion properties of as-cast composites, Tafel and electrochemical impedance spectroscopy (EIS) techniques were performed in simulated body fluid (SBF). In-vitro bioactivity test was also carried out in SBF for 7 days of immersion period. Compression test results have showed that the increase in Al2O3 content up to 10 wt% in Mg-1Sn matrix would increase the compression strength and deteriorate on further increase Al2O3 content. The similar trend was observed in case of corrosion behaviour indicating that beyond 10 wt% of Al2O3, both mechanical and corrosion properties diminish. However, bioactivity performance was almost similar in case of all the composites and was better compared to Mg-1Sn alloy without the addition of Al2O3. Hence, it was concluded that the addition of Al2O3 increases the bioactivity of the Mg-1Sn alloy and up to the 10 wt% addition would enhance the mechanical and corrosion properties and further increase in Al2O3 content, they seem to be declining.