Abstract:The superhydrophobic coatings were prepared on the surface of biomedical Ti-6Al-V alloy by micro-arc oxidation (MAO) and surface modification of fluoroalkyl silane. The effect of voltages on surface morphologies and roughness of the coatings was investigated, and the phase composition and element chemical state of the MAO and hydrophobic treated samples were analyzed to discuss the formation mechanism of the superhydrophobic coating. At the same time, the cytotoxicity and antibacterial property of the superhydrophobic samples were also preliminarily evaluated. The results show that the surface roughness of the coatings increases with increasing the voltages, and the microstructure uniformity of the coatings is optimum at 440 V. After superhydrophobic treatment, the surface roughness of samples decreases slightly compared to the MAO samples, and the contact angles of the samples increase first, and then decrease with increasing the the voltages, reaching the maximum value of 154.9° at 440 V. The MAO coating is mainly composed of anatase TiO2 phase and a little rutile TiO2 phase with a large number of –OH and some phosphorus compounds. While the surface of the superhydrophobic coating contains a large number of CF3, CF2 and Si-O groups.The fluoroalkyl silane is grafted onto the MAO coating through the hydrolytic reaction and dehydration reaction to form the superhydrophobic surface. The superhydrophobic sample belongs to Class 1 non-toxic material, and the cell viability of the superhydrophobic sample has no significant difference from that of Ti-6Al-4V alloy. Moreover, the superhydrophobic sample also has certain antibacterial property, and the antibacterial rate can be up to 93.03% compared to the MAO treated sample.