Enhancement of the shape memory effect by the introductions of Cr and Sn into the β-Ti alloy towards the biomedical applications

JOURNAL OF ALLOYS AND COMPOUNDS

卷:875

Article

Chiu, Wan-Ting¹  Wakabayashi, Kaoru^1,2  Umise, Akira¹  Tahara, Masaki¹  Inamura, Tomonari¹  Hosoda, Hideki¹ 

[1] Tokyo Inst Technol, Inst Innovat Res IIR, Midori Ku, 4259 Nagatsuta Cho, Yokohama, Kanagawa 2268503, Japan

[2] Komatsu Ltd, Minato Ku, 2-3-6 Akasaka, Tokyo 1078414, Japan

关键词: beta-Ti;    Biomedical materials;    Shape memory alloy;    Shape recovery;    Ti-Cr-Sn;   

DOI  :  10.1016/j.jallcom.2021.160088

来源: Elsevier

【 摘 要 】

The effects of the Cr and Sn addition concentrations on the cold-workability, phase constituents, mechanical properties, shape memory effect (SME), and superelasticity were investigated. A systematic screening of the beta-Ti alloy, which was slight-alloyed by Cr and Sn, was executed in this work. Cold-workability of the Ti-Cr-Sn alloys was greatly promoted along with the increasing concentration of Cr and Sn. The parent beta-phase was successfully stabilized at room temperature merely by the slight introduction of Cr and Sn beta-stabilizers. Perfect SME of 100% recovery rate was realized in the Ti-5.5Cr-3Sn alloy and the shape recovery rate performed a good inclination with the overall Cr + Sn addition concentration in the bending tests. Obvious two-stage yielding, which inferred the stress-induced martensitic transformation (SIMT) and/or martensite variant reorientation (MVR) before yielding, was observed in the tensile tests. The two-stage yielding also explained the SME well. The excellent elongation of 40% and 45%, which were found in the Ti-6.0Cr-3Sn and the Ti-6.0Cr-2Sn alloys, was explained by the {332} <113> mechanical twinning. Slight pseudoelasticity was also found in most of the specimens. Functional mappings of the Ti-Cr-Sn alloys, which could be powerful tools for future investigations, have been constructed in this study. The Ti-6.0Cr-3Sn alloy, which possessed high ultimate tensile strength, excellent ductility of 40%, outstanding SME of 91.0%, and good shape recovery after removing the external stress, could be a promising material for the applications in biomedical materials. (C) 2021 Elsevier B.V. All rights reserved.

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