Biocompatible low Young's modulus achieved by strong crystallographic elastic anisotropy in Ti–15Mo–5Zr–3Al alloy single crystal

• Published in: Journal of the mechanical behavior of biomedical materials Vol. 14; pp. 48 - 54
• Main Authors: Lee, S.-H., Todai, M., Tane, M., Hagihara, K., Nakajima, H., Nakano, T.
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier Ltd 01.10.2012
• Subjects: Acoustic methods; Alloy development; Alloys - chemistry; Aluminum - chemistry; Anisotropy; Biocompatibility; Biocompatible Materials - chemistry; Biomaterials; Biomedical materials; Crystallography; Elastic anisotropy; Elastic behavior; Elastic Modulus; Modulus of elasticity; Molybdenum - chemistry; Single crystal; Single crystals; Stress, Mechanical; Surgical implants; Titanium - chemistry; Titanium alloys; Titanium base alloys; Zirconium - chemistry; Titanium alloys; Elastic behavior; Acoustic methods; Single crystal; Biomaterials
• ISSN: 1751-6161; 1878-0180
• DOI: 10.1016/j.jmbbm.2012.05.005

The elastic anisotropy of the Ti–15Mo–5Zr–3Al (mass%) β-Ti alloy, an ISO certified biomedical material, was investigated using its single crystal. It was revealed that the Young's modulus exhibited pronounced anisotropy. The Young's modulus was reduced to 44.4GPa along the 〈100〉 direction in the Ti–15Mo–5Zr–3Al single crystal, that is comparable to that of human cortical bones. We determined the strategy that β-Ti alloys with extremely low moduli can be developed by reducing the electron–atom (e/a) ratio in alloys, and by suppressing the formation of the ω-phase at the same time. This new knowledge must lead to the development of “single crystalline β-Ti implant materials” as hard tissue replacements for reducing the stress shielding effect. ► Elastic anisotropy in the Ti–15Mo–5Zr–3Al alloy was first clarified. ► The alloy shows the strong orientation dependence of the Young's modulus. ► The Young's modulus shows low value of 44.4GPa along the 〈100〉 direction. ► β-Ti alloys having extremely low moduli can be developed by reducing the e/a ratio. ► Strategy for developing the single crystalline β-Ti implant material was established.