Preparation, Microstructure and Bioactivity ofPlasma-Sprayed TiO2 Coating

摘要

In this paper, nano-structured TiO2 coatings have beensuccessfully deposited onto titanium alloy substrates byatmospheric plasma spraying technology using optimizedplasma parameters. A chemical treatment method was employedto induce bioactivity on the TiO2 surface. The bioactivity of assprayed and chemical treated TiO2 coatings were evaluated by investigating the formation of apatite on their surface after they were soaked in simulated body fluids (SBF) for a period of time.Microstructure and the phase composition of the as-sprayed coating and apatite were analyzed by Field-emission scanningelectron microscopy (FESEM), transmission electronmicroscopy (TEM), X-ray diffraction (XRD) and energydispersive X-ray spectrometry (EDS). The results obtained indicate that as-sprayed TiO2 coating consists of rutile, anatase and suboxide such as Ti3O5. The surface of nano-TiO . TiO2 coating is covered by nano particles of about 50nm in size. The bonding strength of TiO2 coating with Ti alloy substrate is as high as 40Mpa. The corrosion resistance performance of nano-coating in SBF is better than that of Ti-6Al-4V alloy. The surface of assprayed TiO2 coating can not induce bone-like apatite formation.Chemical treatment, such as acid and alkali, can improve bioactivity of TiO2 coating surface.