Microstructure and mechanical properties of Ti-Nb-Fe-Zr alloys with high strength and low elastic modulus
(1. School of Mechanical Engineering, University of Shanghai for Science and Technology, Shanghai 200093, China;
2. CAS Key Laboratory of Functional Materials and Devices for Special Environments, Xinjiang Technical Institute of Physics & Chemistry, CAS,Urumqi 830011, China;
3. Division of Mechanical Engineering, Faculty of Science and Engineering, Kindai University, 3-4-1 Kowakae, Higashiosaka, Osaka 577-8502, Japan;
4. School of Materials Science and Engineering, University of Shanghai for Science and Technology,Shanghai 200093, China;
5. Institute for Materials Research, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai 980-8577, Japan;
6. Division of Materials and Manufacturing Science, Graduate School of Engineering, Osaka University, 2-1 Yamada-Oka, Suita, Osaka 565-0871, Japan;
7. Department of Materials Science and Engineering, Graduate School of Science and Technology, Meijo University, 1-501 Shiogamaguchi, Tempaku-ku, Nagoya 468-8502, Japan)
2. CAS Key Laboratory of Functional Materials and Devices for Special Environments, Xinjiang Technical Institute of Physics & Chemistry, CAS,Urumqi 830011, China;
3. Division of Mechanical Engineering, Faculty of Science and Engineering, Kindai University, 3-4-1 Kowakae, Higashiosaka, Osaka 577-8502, Japan;
4. School of Materials Science and Engineering, University of Shanghai for Science and Technology,Shanghai 200093, China;
5. Institute for Materials Research, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai 980-8577, Japan;
6. Division of Materials and Manufacturing Science, Graduate School of Engineering, Osaka University, 2-1 Yamada-Oka, Suita, Osaka 565-0871, Japan;
7. Department of Materials Science and Engineering, Graduate School of Science and Technology, Meijo University, 1-501 Shiogamaguchi, Tempaku-ku, Nagoya 468-8502, Japan)
Abstract: Zr was added to Ti-Nb-Fe alloys to develop low elastic modulus and highstrength β-Ti alloysforbiomedical applications. Ingots of Ti-12Nb-2Fe-(2, 4, 6, 8, 10)Zr (at.%) were prepared by arc melting and then subjected to homogenization, cold rolling, and solution treatments. The phases and microstructures of the alloys were analyzed by optical microscopy, X-ray diffraction, and transmission electron microscopy. The mechanical properties were measured by tensile tests. The results indicate that Zr and Fe cause a remarkable solid-solutionstrengthening effect on the alloys; thus, all the alloys show yield and ultimate tensile strengths higher than 510 MPa and 730 MPa, respectively. Zr plays a weak role in the deformation mechanism. Further, twinning occurs in all the deformed alloys and is beneficial to both strength and plasticity. Ti-12Nb-2Fe-(8, 10)Zr alloys with metastable β phases show low elastic modulus, high tensile strength, and good plasticity and are suitable candidate materials for biomedical implants.
Key words: biomedical Ti alloy;mechanical properties;solid-solution strengthening;work hardening;twinning-induced plasticity