Shape memory characteristics of Ti–22Nb–(2–8)Zr(at.%) biomedical alloys

Shape memory characteristics of Ti–22Nb–(2–8)Zr(at.%) biomedical alloys were investigated by using tensile tests and X-ray diffraction (XRD) measurement. The alloy ingots were fabricated by an arc melting method. The ingots were cold-rolled by a reduction up to 95% in thickness at room temperature. All the alloys were solution-treated at 1173 K for 1.8 ks. The alloys subjected to the solution treatment exhibited large elongations ranging between 28 and 40%. The martensitic transformation temperature decreased by 38 K with 1 at.% increase of Zr content. The maximum recovered strain of 4.3% was obtained in the Ti–22Nb–4Zr(at.%) alloy. Ti–22Nb–(2–4)Zr(at.%) and Ti–22Nb–6Zr(at.%) alloys exhibited stable shape memory effect and superelastic behavior at room temperature, respectively.