Ti6Al4V表面HAP/TiO_2生物活性复合涂层的表征及结合强度分析

Characterisation and mechanical adhesion of HAP/TiO_2 composite films on Ti6Al4V processed by sol-gel method

采用溶胶-凝胶法在Ti6Al4V基体上制备了HAP/TiO2纳米复合涂层,并引入TiO2作为缓冲层.使用XRD、FT-IR和FE-SEM协同EDS研究了450、550和650℃温度下煅烧后涂层的组成和结构特征.实验结果表明,HAP/TiO2涂层均具有较好的结晶态,涂层厚度均匀、致密,与金属基体结合紧密.由亚微米级HAP晶体颗粒(100～200nm)镶嵌在分布均匀的纳米TiO2胶质之中,TiO2凝胶颗粒大小随煅烧温度的变化在10～30nm变动.力学测试结果表明这些复合涂层具有较高的结合强度,随着煅烧温度的升高,涂层的抗拉强度呈现上升的趋势.体外生物活性的测试证实了它们的生物活性.

The composite films consisting of hydroxyapatite (HAP) submicron crystals (100-200 nm) embedded in the matrix of the titania gel were prepared on commercial Ti6Al4V plates with titania buffer layer by a spin-coating technique. The films were annealed in air at 450, 550 and 650°C, respectively. The phase formation, surface morphology, and interfacial microstructure of the films were investigated by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), field emission-scanning electron microscopy (FE-SEM) and Energy dispersive X-ray (EDS) analysis. The results showed that the as-prepared films were well-crystallized, dense, homogeneous, and there was a close interfacial bonding between the film and the substrate. To some extent the crystallized phase transitions between anatase and rutile in the composite films were suppressed. With the increasing of annealing temperature, sizes of TiO2 crystals increased in the range of 10-30 nm. The results of adhesion test indicated that there was a good bonding strength within the film and at substrate-film interface, which changed a little with the various annealing temperatures. The formation of bone-like apatite on the surfaces of the films after immersed in simulated body fluid (SBF) validated their bioactivities.