T. Ishigaki, Y. Matsuki, T. Inamura, K. Wakashima, H. Hosoda, Tokyo Institute of Technology, Yokohama, Japan; S. Miyazaki, University of Tsukuba, Tsukuba, Japan
Shape memory (SMA) and superelastic (SE) alloys are applied for biomaterials because of the unique mechanical properties. Recently, Ti-Ni alloys are mainly used in this field. However, it is pointed out that Ni element is toxic for human body. Then, the development of Ti-base new SMA and SE alloys, which do not contain harmful elements like Ni, is required. We have focused on Au as an additional element due to its good corrosion resistance and high contrast in X-ray picture. A eutectoid Ti-4mol%Au alloy was examined in this study as a basic research. The Ti-Au binary alloy quenched from β-phase region was single phase of α (hcp),phase which was formed by a massive transformation. In this study, the change in phase constitution and mechanical properties was evaluated for the Ti-Au alloys containing 3d transition metal elements such as Fe. For instance, 4mol%Fe addition stabilizes β-phase at room temperature and ultimate tensile strength reaches 900MPa.
Summary: Shape memory (SMA) and superelastic (SE) alloys are applied for biomaterials because of the unique mechanical properties. Recently, Ti-Ni alloys are mainly used in this field. However, it is pointed out that Ni element is toxic for human body. Then, the development of Ti-base new SMA and SE alloys, which do not contain harmful elements like Ni, is required.
We have focused on Au as an additional element due to its good corrosion resistance and high contrast in X-ray picture. A eutectoid Ti-4mol%Au alloy was examined in this study as a basic research. The Ti-Au binary alloy quenched from
b-phase region was single phase of
a (hcp),phase which was formed by a massive transformation. In this study, the change in phase constitution and mechanical properties was evaluated for the Ti-Au alloys containing 3d transition metal elements such as Fe. For instance, 4mol%Fe addition stabilizes
b-phase at room temperature and ultimate tensile strength reaches 900MPa.
