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

► 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 44.4 GPa 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.