Study On The Bioactivity Treatment And Hydroxyapatite Deposition Induced Of Titanium Surface

As the development of economy and the progress of society, biomaterials are studied more widely. Improving the bioactivity is one of the most important in the study of metallic-based biomedical materials. Titanium alloy has high specific strength and good corrosion resistance. However, titanium has no good bioactivity. When titanium was planted into body directly, it is easy to form fibrous connective tissue and hard to form chemical bond combining with surround bone tissue. HA has excellent biocompatibility and bioactivity, which is the main chemical composition of human bone. When hydroxyl apatite is deposited on the surface of titanium alloy, it has both the advantages of metallic materials and bioactive ceramic materials, and can be used as a kind of perfect bone tissue implant materials.SBF cultivation experiments were done with the samples of alkali treatment and SiO₂ films deposited by PACVD on Ti respectively in this passage with the aim of obtaining some HA. The microstructures and compositions were observed and analyzed with the methods of SEM and XPS. Good process of alkali treatment and SiO₂ films deposited by PACVD to form HA were obtained.The results show that alkali concentration and treating time have obvious influence on netlike structure. Temperature has small influence on surface topography. When SiO₂ films were deposited by PACVD, rather pure SiO₂ functional films can be obtained through process optimization. HA coatings were deposited on the samples of alkali treatment and SiO₂ films deposited respectively.The proper process of depositing HA after alkali treatment is that Titanium is dealed with in 10mol/l NaOH for 24h and immersed in 5 SBF at 60℃, then so many HA are deposited on the surface. The quantity of HA are increased as the immersing time goes by.The proper process of depositing HA after SiO₂ films deposited on titanium by PACVD is that 40 nm thick rather pure SiO₂ functional films can be obtained by taking the following parameters: 5×10^-1 Torr chamber pressure, 8℃water bath temperature, 10 sccm air and 30 min. Granular HA were formed uniformly on the surface after immersed in 15Ca/P-5SBF for 7d. Diameter of HA is about 300nm.