Investigation of Properties of TiO2/MgO Dual Layer Thin Film Formed by Magnetron Sputtering on Mg Alloy

Abstract     Nowadays, magnesium alloys such as a new generation of biodegradable materials have been noticed by researchers. In this study, to the sanitation of biodegradability and biocompatibility of magnesium alloys, TiO2/MgO dual layer coating was formed by magnetron sputtering on AZ91 and the microstructure, corrosion behavior and biocompatibility properties of coating were investigated. The coating microstructure was studied via field emission scanning electron microscopy (FESEM) X-ray diffraction (XRD). The corrosion resistance of the substrate and coated sample was evaluated by electrochemical polarization test in simulated body solution (SBF). To evaluate biocompatibility MTT and cell viability tests were used. The results showed that the corrosion potential after the surface coating with TiO2/ MgO was more positive, changing from 1.532 V for the uncoated sample to 1.436 V for the coated sample.. The coating was observed in quasi-spherical morphology with MgTi2O5 and MgTiO3 phases in interface of coating and substrate and two layers of coating too according to XRD analysis results. The results of the biocompatibility tests also showed that the viability of the osteoblastic cells on the coated sample increased compared to substrate.