表面改質加工（EG-X）法によるNi-Ti形状記憶合金の高品位表面仕上げとその改質効果の検討

摘要

形状記憶合金のなかでNi-Ti合金は，形状記憶効果や超弾性などの機能に加え，Ti系生体材料に近い健れた耐食性を有することから，医療分野における応用が期待されている．とくに形状回復時に発生する復元力や超弾性を利用して，固定力や矯正力が要求される骨折治療や脊椎側わん症の治療に利用することができれば，治療期間の飛躍的な短縮が期待できるものと著者らは考えている．%Nickel-Titanium (Ni-Ti) alloy is known for its shape memory properties. These properties are useful for various biomedical applications. However, a high percentage of nickel elements in Ni-Ti alloy elicit toxicity, allergic responses, and limits practical uses of the alloy. Therefore, further improvement of the corrosion resistance of Ni-Ti alloy is desirable for implant applications. In this study, the authors conducted a study by using Ni-Ti alloy on the new compound surface modification method consisting of a new electrical grinding technique (EG-X) based on ELID (Electrolytic In-process Dressing) grinding and Thermal Oxidation (TO). The results showed that the new compound surface modification method can achieved high quality surface compared with the conventional TO treated surface.