Microstructure and Mechanical Properties of a Biomedical β-Type Titanium Alloy Subjected to Severe Plastic Deformation after Aging Treatment

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Abstract:

Strengthening by Grain Refinement and Increasing Dislocation Density through High-Pressure Torsion (HPT), which Is an Attractive Technique to Fabricate Ultrafine Grained and Nanostructured Metallic Materials, Is Expected to Provide β-Type Ti-29Nb-13Ta-4.6Zr (TNTZ) Higher Mechanical Strength while Maintaining Low Young’s Modulus because they Keep the Original β Phase. However, the Ductility Shows Reverse Trend. Greater Strength with Enhanced Ductility Can Be Achieved by Controlling Precipitated Phases through HPT Processing after Aging Treatment. Aged TNTZ Subjected to HPT Processing at High N Exhibits a Homogeneous Microstructure with Ultrafine Elongated Grains Having a High Dislocation Density and Consequently Non-Equilibrium Boundaries and Distorted Subgrains with Non-Uniform Shapes and Nanostructured Intergranular Precipitates of αphases. Therefore, the Effect of HPT Processing on the Microstructure and Mechanical Hardness of TNTZ after Aging Treatment Was Systematically Investigated in this Study. TNTZ, which Was Subjected to Aging Treatment at 723 K for 259.2 Ks in Vacuum Followed by Water Quenching, Subjected to HPT Processing at Rotation Numbers (N) of 1 to 20 under a Pressure of around 1.25 GPa at Room Temperature. The Microstructure of TNTZAT Consisted of Precipitated Needle-Like α Phases in β Grains. However, TNTZAHPT at N ≥ 10 Comprises Very Fine α and Small Amount ω Phases in Ultrafine β Grains. Furthermore, the Hardness of Every TNTZAHPT Was Totally much Greater than that of TNTZAT. The Hardness Increased from the Center to Peripheral Region of TNTZAHPT. In Addition, the Tensile Strength of Every TNTZAHPT Was Greater than that of TNTZAT. The Tensile Strength of TNTZAHPT Increased, but the Elongation Decreased with Increasing N and then both of them Saturated at N ≥ 10.

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March 2012

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[1] M. Niinomi, Mechanical biocompatibilities of titanium alloys for biomedical applications, J. Mech. Behav. Biomater. I (2008) 30–42.

Google Scholar

[2] T. Akahori, M. Niinomi, H. Fukui, and A. Suzuki, Fretting fatigue and corrosion characteristics of biocompatible beta type titanium alloy conducted with various thermo-mechanical treatments, Mater. Trans. 45 (2004) 1540–1548.

DOI: 10.2320/matertrans.45.1540

Google Scholar

[3] T. Akahori, M. Niinomi, H. Fukui, M. Ogawa, and H. Toda, Improvement in fatigue characteristics of newly developed beta type titanium alloy for biomedical applications by thermo-mechanical treatments, Mater. Sci. Eng. C 25 (2005) 248–254.

DOI: 10.1016/j.msec.2004.12.007

Google Scholar

[4] D. Kuroda, M. Niinomi, M. Morinaga, Y. Kato, and T. Yashiro, Design and mechanical properties of new β type titanium alloys for implant materials, T., Mater. Sci. Eng. 243 (1998) 244–249.

DOI: 10.1016/s0921-5093(97)00808-3

Google Scholar

[5] M. Niinomi, Mechanical properties of biomedical titanium alloys, Mater. Sci. Eng. A 243 (1998) 231–236.

Google Scholar

[6] H. Yilmazer, M. Niinomi, T Akahori, M. Nakai, and Y. Todaka, Effect of high-pressure torsion processing on microstructure and mechanical properties of a biomedical β-type titanium alloy, Int. J. Microst. Mater. Proper., in press.

DOI: 10.1504/ijmmp.2012.047498

Google Scholar

[7] F. Geng, M. Niinomi, and M. Nakai, Observation of yielding and strain hardening in a titanium alloy having high oxygen content, Mater. Sci. Eng. A 528 (2011) 5435–5445.

DOI: 10.1016/j.msea.2011.03.064

Google Scholar

[8] X. Song, M. Niinomi, H. Tsutsumi, M. Nakai, L. Wang, Effects of TiB on the mechanical properties of Ti-29Nb-13Ta-4. 6Zr alloy for use in biomedical applications, Mater. Sci. Eng. A 528 (2011) 5600–5609.

DOI: 10.1016/j.msea.2011.03.108

Google Scholar

[9] M. Nakai, M. Niinomi, and T. Oneda, Improvement in fatigue strength of biomedical b-type Ti-Nb-Ta-Zr alloy while maintaining low Young's modulus through optimizing w-phase precipitation, Metall. Mater. Trans. A, in press.

DOI: 10.1007/s11661-011-0860-3

Google Scholar

[10] R.Z. Valiev, R.K. Islamgaliev, and I.V. Alexandrov, Bulk nanostructured materials from severe plastic deformation, Prog. Mater. Sci. 45 (2000) 103–189.

DOI: 10.1016/s0079-6425(99)00007-9

Google Scholar

[11] A.P. Zhilyaev and T.G. Langdon, Using high-pressure torsion for metal processing: Fundamentals and applications, Prog. Mater. Sci. 53 (2008) 893–979.

DOI: 10.1016/j.pmatsci.2008.03.002

Google Scholar

[12] R.K. Islamgaliev, Bulk nanostructured materials from severe plastic deformation, Prog. Mater. Sci. (2000) 45–103.

Google Scholar

[13] Y. Iwahashi, Z. Horita, M. Nemoto, and T.G. Langdon, Factors influencing the equilibrium grain size in equal-channel angular pressing: Role of Mg additions to aluminum, Metall. Mater. Trans. 29 (1998) 2503–2510.

DOI: 10.1007/s11661-998-0222-y

Google Scholar

[14] Z. Horita, D.J. Smith, M. Furukawa, N. Memoto, R.Z. Valiev, and T. G Langdon, An investigation of grain boundaries in submicrometer-grained Al-Mg solid solution alloys using high-resolution electron microscopy, J. Mater. Res. 11 (1996) 1880–1890.

DOI: 10.1557/jmr.1996.0239

Google Scholar

[15] R.S., Mishra V.V. Stolyarov, C. Echert, R.Z. Valiev, and A.K. Mukherjee, Mechanical behavior and superplasticity of a severe plastic deformation processed nanocrystalline Ti–6Al–4V alloy, Mater. Sci. Eng. A 298 (2001) 44–50.

DOI: 10.1016/s0921-5093(00)01338-1

Google Scholar

[16] A.V. Korznikov, G. Tram, O. Dimitrov, G.F. Korznikova, S.R. Idrisova, and Z. Pakiela, The mechanism of nanocrystalline structure formation in Ni3Al during severe plastic deformation, Acta Mater. 49 (2001) 663–671.

DOI: 10.1016/s1359-6454(00)00345-1

Google Scholar

[17] Y. Zhao and J. Zhang, Microstrain and grain-size analysis from diffraction peak width and graphical derivation of high-pressure thermomechanics, J. Appl. Cryst. 41 (2008) 1095–1108.

DOI: 10.1107/s0021889808031762

Google Scholar

[18] T. Ungar, S. Ott, P.G. Sanders, A. Borbealy, and J.R. Weertman, Dislocations, grain size and planar faults in nanostructured copper determined by high resolution X-ray diffraction and a new procedure of peak profile analysis, Acta Mater. 46 (1998).

DOI: 10.1016/s1359-6454(98)00001-9

Google Scholar

[19] L. Li, T. Ungár, Y.D. Wang, J.R. Morris, G. Tichy, J. Lendvai, Y.L. Yang, Y. Ren, H., Choo, and P.K. Liaw, Microstructure evolution during cold rolling in a nanocrystalline Ni–Fe alloy determined by synchrotron X-ray diffraction, Acta Mater. 57 (2009).

DOI: 10.1016/j.actamat.2009.07.002

Google Scholar

[20] T. Ungár, Microstructural parameters from X-ray diffraction peak broadening, Scrip. Mater. 51 (2004) 777–781.

DOI: 10.1016/j.scriptamat.2004.05.007

Google Scholar

[21] T. Furuhara, T. Maki, and T. Makino, Microstructure control by thermomechanical processing in β-Ti–15–3 alloy, J. Mater. Proc. Tech. 117 (2001) 318–323.

DOI: 10.1016/s0924-0136(01)00790-7

Google Scholar

[22] Y. Todaka, J. Sasaki, T. Moto, and M. Umemoto, Bulk submicrocrystalline ω-Ti produced by high-pressure torsion straining, Scripta Mater. 59(6) (2008) 615–618.

DOI: 10.1016/j.scriptamat.2008.05.015

Google Scholar

[23] Z. Horita and T.G. Langdon, Microstructures and microhardness of an aluminum alloy and pure copper after processing by high-pressure torsion, Mater. Sci. Eng. A 410–411 (2005) 422–425.

DOI: 10.1016/j.msea.2005.08.133

Google Scholar

[24] G. Sakai, K. Nakamura, Z. Horita, and T.G. Langdon, Developing high-pressure torsion for use with bulk samples, Mater. Sci. Eng. A 406 (2005) 268–273.

DOI: 10.1016/j.msea.2005.06.049

Google Scholar

[25] A.P. Zhilyaev, K. Oh-ishi, T.G. Langdon, and T.R. McNelley, Microstructural evolution in commercial purity aluminum during high-pressure torsion, Mater. Sci. Eng. A 410–411 (2005) 277–280.

DOI: 10.1016/j.msea.2005.08.044

Google Scholar

[26] A.P. Zhilyaev, S. Lee, G.V. Nurislamova, R.Z. Valiev, and T.G. Langdon, Microhardness and microstructural evolution in pure nickel during high-pressure torsion, Scripta Mater. 44 (2001) 2753–2758.

DOI: 10.1016/s1359-6462(01)00955-1

Google Scholar

[27] A. Vorhauer, R. Pippan, On the homogeneity of deformation by high pressure torsion, Scripta Mater. 51 (2004) 921–925.

DOI: 10.1016/j.scriptamat.2004.04.025

Google Scholar