Microstructure, degradation properties and cytocompatibility of micro-arc oxidation coatings on the microwave sintered Ti-15Mg metal-metal composite

The micro-arc oxidation (MAO) coatings were fabricated on the surface of the microwave sintered Ti-15Mg metal-metal composite (MMC). The surface morphologies, phase composition, degradation properties and cytocompatibility of the MAO treated Ti-15Mg MMC were investigated. The XRD and XPS results show that the MAO coatings are mainly composed of anatase and rutile TiO2 crystal phases and amorphous MgO and SiO2 with some –OH groups. There are some differences between MAO pore structure in Ti region and Mg region, but both of the pore sizes increase and the number of pores decreases with increasing the applied voltages. The degradation rate of Ti-15Mg MMC is reduced by the MAO coatings, and with increasing the applied voltages, the degradation rates of the MAO treated samples decrease first, reaching the minimum value at 300 V, and then increase. After immersed in SBF solution for 250 h, the calcium-deficient apatite containing CO32− is detected on the surface of the MAO treated and untreated Ti-15Mg MMC. The results of cell viability and alkaline phosphatase activity show that the MAO treated Ti-15Mg MMCs are more conducive to the proliferation and differentiation of MG-63 cells.