High pressure torsion induced lowering of Young's modulus in high strength TNZT alloy for bio-implant applications

T Maity; Ö Balcı; C Gammer; E Ivanov; J Eckert; K G Prashanth

doi:10.1016/j.jmbbm.2020.103839

High pressure torsion induced lowering of Young's modulus in high strength TNZT alloy for bio-implant applications

J Mech Behav Biomed Mater. 2020 Aug:108:103839. doi: 10.1016/j.jmbbm.2020.103839. Epub 2020 May 4.

Authors

T Maity¹, Ö Balcı², C Gammer³, E Ivanov⁴, J Eckert⁵, K G Prashanth⁶

Affiliations

¹ National Institute of Foundry and Forge Technology, Hatia, Ranchi, 834003, India; Department of Materials Science, Montanuniversitat Leoben, Jahnstraße 12, A-8700, Leoben, Austria; Erich Schmid Institute of Materials Science, Austrian Academy of Sciences, Jahnstraße 12, A-8700, Leoben, Austria.
² Department of Chemistry, Koç University, Rumelifeneri Yolu, 34450, Sarıyer, İstanbul, Turkey.
³ Erich Schmid Institute of Materials Science, Austrian Academy of Sciences, Jahnstraße 12, A-8700, Leoben, Austria.
⁴ Tosoh SMD Inc., Grove City, OH, 43123, USA.
⁵ Department of Materials Science, Montanuniversitat Leoben, Jahnstraße 12, A-8700, Leoben, Austria; Erich Schmid Institute of Materials Science, Austrian Academy of Sciences, Jahnstraße 12, A-8700, Leoben, Austria.
⁶ Erich Schmid Institute of Materials Science, Austrian Academy of Sciences, Jahnstraße 12, A-8700, Leoben, Austria; Department of Mechanical and Industrial Engineering, Tallinn University of Technology, Ehitajate tee 5, 19086, Tallinn, Estonia; CBCMT, School of Mechanical Engineering, VIT University, Vellore, 632 014, Tamil Nadu, India. Electronic address: kgprashanth@gmail.com.

PMID: 32469711
DOI: 10.1016/j.jmbbm.2020.103839

Abstract

An exceptional combination of low Young's modulus (E ~68 GPa) and high flow strength (σ_f ~1 GPa) was achieved for a consolidated β-Ti-based metastable Ti-35Nb-7Zr-5Ta (TNZT) alloy subjected to room temperature high-pressure torsion (HPT). The mechanical properties of the alloy were studied by quasistatic nanoindentation tests at different strain rates, where a reduction in Young's modulus E ~73 GPa (N_HPT¹⁰) and E ~68 GPa (N_HPT⁴⁰) is observed together with an increase in plastic deformability (or HPT rotations). The microstructure evolution with increasing shear strain has been investigated. The stabilized bcc β-Ti phase with homogeneous nanostructure distribution was observed leading to a low Young's modulus. Severe straining causes a uniform hardness distribution without any noticeable change in the strength of the material. This study may be useful for developing excellent removable implant materials.

Keywords: Activation volume; High-pressure torsion; Micro-/nanoindentation; Strain-rate sensitivity; Young's modulus; β-Ti alloy.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Alloys*
Elastic Modulus
Hardness
Prostheses and Implants
Titanium*

Substances

Alloys
Titanium