Y. Sutou, A. Furukawa, M. Suzuki, K. Yamauchi, Tohoku University, Sendai, Japan; M. Nishida, Kyushu University, Kasuga, Japan
Recently, shape memory alloy (SMA) wires and tubes with superelasticity (SE) are attracting considerable attention as core materials for minimally invasive surgical devices such as guidewires, catheters, stents, and so on. Although Ti-Ni SMAs possessing excellent SE are currently widely used in such medical devices, the toxicity and hypersensitivity of Ni have been problematic. Thus, the development of biocompatible Ni-free SMAs is strongly required.
In the present study, Ti-Mo-Sn-based SE tubes have been developed. Ti-Mo-Sn and Ti-Mo-Sn-Sc alloys were prepared by cold crucible induction melting. The cast alloy was hot-forged and hot-rolled. Ti-Mo-Sn(-Sc) tubes with various diameters were fabricated by 3-roll rolling and cold-drawing.
The SE of Ti-Mo-Sn alloys can be enhanced by the addition of Sc. The tubes also show good flexibility and SE. Since Ni-free Ti-Mo-Sn-based alloys possess high corrosion resistance and excellent biocompatibility, new class of metallic flexible catheters with a fine diameter and thin walls, and Ni-free self-expandable stent can be expected.
Summary: The SE of Ti-Mo-Sn alloys can be enhanced by the addition of Sc. The tubes also show good flexibility and SE. Since Ni-free Ti-Mo-Sn-based alloys possess high corrosion resistance and excellent biocompatibility, new class of metallic flexible catheters with a fine diameter and thin walls, and Ni-free self-expandable stent can be expected.
