TY - JOUR
T1 - Development of thermo-mechanical processing for fabricating highly durable β-type Ti-Nb-Ta-Zr rod for use in spinal fixation devices
AU - Narita, Kengo
AU - Niinomi, Mitsuo
AU - Nakai, Masaaki
AU - Hieda, Junko
AU - Oribe, Kazuya
N1 - Funding Information:
The authors thank Mr. Ueta, Daido Steel Co., Ltd., for melting the alloy and Mr. Suzuki, Yoshida Kinen Shohji for conducting cold swaging. This work was supported in part by the Global COE Program, “Materials Integration (International Center of Education and Research)” of Tohoku University; the Ministry of Education, Culture, Sports, Science and Technology (MEXT), Japan ; the Inter-University Cooperative Research Program, “Highly-Functional Interface Science: Innovation of Biomaterials with Highly Functional Interface to Host and Parasite” of Tohoku University and Kyushu University; MEXT, Japan; Grants-in-Aid for Young Scientists (B); the Japan Society for the Promotion of Science (JSPS), Japan ; the Research Seeds Quest Program, Japan Science and Technology Agency (JST) , Japan; the Industrial Technology Research Grant Program in 2009 from the New Energy and Industrial Technology Development Organization (NEDO), Japan ; the Cooperative Research Program of the Institute for Materials Research, Tohoku University, Japan ; and the Cooperative Research Program of the Advanced Research Center of Metallic Glasses , Institute for Materials Research, Tohoku University, Japan.
PY - 2012/5
Y1 - 2012/5
N2 - The mechanical strength of a beta titanium alloy such as Ti-Nb-Ta-Zr alloy (TNTZ) can be improved significantly by thermo-mechanical treatment. In this study, TNTZ was subjected to solution treatment, cold caliber rolling, and cold swaging before aging treatment to form a rod for spinal fixation. The . {110}β are aligned parallel to the cross-section with two strong peaks approximately 180. {ring operator} apart, facing one another, in the TNTZ rods subjected to cold caliber rolling and six strong peaks at approximately 60. {ring operator} intervals, facing one another, in the TNTZ rods subjected to cold swaging. Therefore, the TNTZ rods subjected to cold swaging have a more uniform structure than those subjected to cold caliber rolling. The orientation relationship between the . α and . β phases is different. A . [110]β//. [121]α, . (112)β//. (210)α orientation relationship is observed in the TNTZ rods subjected to aging treatment at 723 K after solution treatment and cold caliber rolling. On the other hand, a . [110]β//. [001]α, . (112)β//. (200)α orientation relationship is observed in TNTZ rod subjected to aging treatment at 723 K after cold swaging. A high 0.2% proof stress of about 1200 MPa, high elongation of 18%, and high fatigue strength of 950 MPa indicate that aging treatment at 723 K after cold swaging is the optimal thermo-mechanical process for a TNTZ rod.
AB - The mechanical strength of a beta titanium alloy such as Ti-Nb-Ta-Zr alloy (TNTZ) can be improved significantly by thermo-mechanical treatment. In this study, TNTZ was subjected to solution treatment, cold caliber rolling, and cold swaging before aging treatment to form a rod for spinal fixation. The . {110}β are aligned parallel to the cross-section with two strong peaks approximately 180. {ring operator} apart, facing one another, in the TNTZ rods subjected to cold caliber rolling and six strong peaks at approximately 60. {ring operator} intervals, facing one another, in the TNTZ rods subjected to cold swaging. Therefore, the TNTZ rods subjected to cold swaging have a more uniform structure than those subjected to cold caliber rolling. The orientation relationship between the . α and . β phases is different. A . [110]β//. [121]α, . (112)β//. (210)α orientation relationship is observed in the TNTZ rods subjected to aging treatment at 723 K after solution treatment and cold caliber rolling. On the other hand, a . [110]β//. [001]α, . (112)β//. (200)α orientation relationship is observed in TNTZ rod subjected to aging treatment at 723 K after cold swaging. A high 0.2% proof stress of about 1200 MPa, high elongation of 18%, and high fatigue strength of 950 MPa indicate that aging treatment at 723 K after cold swaging is the optimal thermo-mechanical process for a TNTZ rod.
KW - Aging treatments
KW - Beta-type
KW - Biomaterials
KW - Cord working
KW - Fatigue strength
KW - Mechanical properties
KW - Spinal devices
KW - Titanium alloys
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U2 - 10.1016/j.jmbbm.2012.01.011
DO - 10.1016/j.jmbbm.2012.01.011
M3 - Article
C2 - 22498297
AN - SCOPUS:84859489476
VL - 9
SP - 207
EP - 216
JO - Journal of the Mechanical Behavior of Biomedical Materials
JF - Journal of the Mechanical Behavior of Biomedical Materials
SN - 1751-6161
ER -