1997 Fiscal Year Final Research Report Summary
Preparation of Bioactive Metals by Chemical Treatments
Project/Area Number |
07559008
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Research Category |
Grant-in-Aid for Scientific Research (A)
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Allocation Type | Single-year Grants |
Section | 展開研究 |
Research Field |
広領域
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Research Institution | KYOTO UNIVERSITY |
Principal Investigator |
KOKUBO Tadashi Kyoto University, Faculty of Engineering, Professor, 工学研究科, 教授 (30027049)
|
Co-Investigator(Kenkyū-buntansha) |
YOSHIHARA Satoshi Nippon Electric Glass Co., Ltd., Researcher, 研究員
NAKAMURA Takashi Kyoto University, Faculty of Medicine, Professor, 医学研究科, 教授 (10201675)
MIYAJI Fumiaki Kyoto University, Faculty of Engineering, Instructor, 工学研究科, 助手 (80219782)
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Project Period (FY) |
1995 – 1997
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Keywords | Chemical treatment / Apatite / Titanium metal / Alkali treatment / Bioactivity |
Research Abstract |
When pure Ti, Ti-6Al-4V,Ti-6Al-2Nb-Ta and Ta-15Mo-5Zr-3Al alloys, SUS316L (stainless) and Co-Cr-Mo alloy which were subjected to NaOH aqueous and heat treatments at 600゚C were soaked in simulated body fluid with ion concentrations nearly equal to those of human blood plasma (SBF), the Ti and its alloys formed a dense and uniform bonelike apatite layr on their surfaces in a short period, whereas the SUS316L and Co-Cr-Mo alloys never did. The reason for the apatite formation on the Ti and its alloys by the alkali treatment is interpreted as follows. The hydrated titania gel formed on the surfaces of the Ti and its alloys in SBF might induce the apatite nucleation and the sodium ions released from the surface layr into the SBF might enhance the apatite nucleation by increasing the degree of supersaturation of the SBF with respect to the apatite. The induction period for the apatite formation on the pure Ti in SBF decreased with increasing concentration of NaOH solution in the case without heat treatment. This result is explained by assuming that as NaOH concentration increases, the amount of sodium ions which were incorporated in the gel layr and then released into SBF increased, giving rise to a rapid increase in the degree of supersaturation of the surrounding fluid. The surface gel layr without heat treatment was, however, liable to be peeled off. When the NaOH-treated Ti was heat treated around 600゚C,the mechanically weak gel layr was converted to the mechanicallystable one without losing its high apatite-forming ability. Tantalum and zirconium metals also formed the apatite on their surfaces by the similar alkaline solution treatment in a short period. In conclusion, the present chemical treatment is a quite simple and effective method for inducing the bioactivity of various metallic materials.
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Research Products
(16 results)