Huazi Jin

Effect of Surface Morphology and Crystal Structure on Bioactivity of Titania Films Formed on Titanium Metal via Anodic Oxidation in Sulfuric Acid Solution

tyxiong@imr.ac.cn Department of Material Chemistry, Graduate School of Engineering, Kyoto University, Sakyo-ku, Kyoto 606-8501, Japan Department of Ceramic Engineering, School of Advanced Materials Engineering, Yonsei University 134 Shinchon-dong, Seodaemun-gu, Seoul 120-749, Korea Research Institute for Science and Technology, Chubu University, 1200 Matsumoto-cho, Kasugai-shi, Aichi 487-8501, Japan Department of Orthopaedic Surgery, Graduate School of Medicine, Kyoto University, Sakyo-ku, Kyoto 606-8507, Japan

Study of Corrosion Resistance of Anodized Ti6Al4V in SBF

A layer of amorphous thick anodic oxide film was formed on Ti6Al4V substrate after anodization, and its thickness achieved 30-40µm. After immersion in SBF, anodized sample and substrate indicated different corrosion resistance. According to icorr, Rp and Ecorr, the concerned experimental results of potentiodynamic polarization curves, the anodic oxide film provided effective corrosion protection, which could be attributed to its relatively uniform, smooth, compact and intact microstructure. And the results of total immersion test also proved the protective role of the anodic film.

Friction and Wear Properties of Cold Gas Dynamic Sprayed Composite Coatings

Different proportions of α-Al2O3 and pure Al powders were coated onto AZ91D magnesium alloy substrates by cold gas dynamic spray. The microstructure and morphologies of the coatings were observed by scanning electron microscope. The friction and wear properties were tested by a ball-on-disk wear tester. It was found that the interfaces between grains and substrates formed close boundaries. It is revealed that the composite coatings could increase the friction or wear properties of the coatings. It was observed that the wear of coatings was converted from adhesive wear into abrasive wear with α-Al2O3 particles increasing and that the adhesive wear accompanied with abrasive wear would increase the wear rate of coatings.

Study on the Bioactivity of Anodic Oxidized Titanium Alloy Induced by Alkali Treatment

Alkali treatment induced to form bonelike apatite layer on the surface of the anodic oxidized Ti6Al4V in 1.5 SBF. It was observed that some spherical apatite crystals were deposited on the surface of the sample for only 1 d. They gradually grew to cover the whole surface of the sample with further increasing soaking time. After 7 days of soaking in 1.5 SBF, apatite covered all the surfaces of the titanium alloys, and they packed very densely and uniformly. At the same time, large amount of new-formed apatite nuclei occurred on the first layer of apatite. The EDS and XRD results proved that all the new-formed phases were composed of apatite. Mechanism of the bioactivity of the anodic oxidized titanium alloys was related to the Ti-OH group formation, and the Ti-OH group would induce apatite formation in SBF.

Preparation of Bioactive Titanium Alloy Implant and Its Histological Examination

A layer of thick oxide film was formed on Ti6Al4V substrate by anodization. Subsequently alkali and heat treatment induced to form bonelike apatite layer on its surface in SBF for 7 days. The performances of the implants in vivo were observed by naked eyes and H.E. staining technique. The bone tissues around the surface and interface of the specimen in treated Ti6Al4V group were formed more quickly than those in Ti6Al4V and 316L alloy groups. H.E staining results of treated Ti6Al4V group showed the development of newly formed bone tissues on the implant-bone interface area.