Journal Article

High tensile strength and transformation-induced plasticity in bulk polycrystalline omega titanium

Sasaki, Keita, Kuramochi, Koji, Fujimura, Akio, Tange, Yoshinori, Matsushita, Masafumi, Wakai, Fumihiro, Tokuda, Kazuya, Nishiyama, Norimasa, Kobayashi, Yutaka, Tominaga, Kosuke, Sawahata, Takashi, Sekiya, Takashi, Horita, Zenji

2026

Overview

Titanium and its alloys exhibit advantageous ductility and strength-to-weight ratios, which makes them suitable for use as structural materials in numerous industrial applications. The ω phase has been observed to precipitate during the aging process of titanium alloys, resulting in a loss of ductility. Here we report tensile behavior of bulk polycrystalline ω-titanium with a chemical composition of commercially pure titanium grade 4 and an average grain size of 3.4 μm. We observed that stress-induced ω → α martensitic phase transformation occurs exclusively in the plastic regime. As plastic deformation proceeds, the volume fraction of α-phase increases. The 0.2% offset yield strength, tensile strength, and elongation to failure were determined to be 1130 ± 30 MPa, 1220 ± 30 MPa, and 16 ± 2%, respectively. The present study revealed transformation-induced plasticity in this material. The mechanical properties of this material with the pure titanium composition are comparable to those of a titanium alloy Ti-6Al-4 V. The bulk polycrystalline ω-titanium can potentially be utilized for biomedical applications, such as dental implants.

• Publisher: Nature Publishing Group UK,Nature Publishing Group,Nature Portfolio
• Subject: 639/166 / 639/301 / Alloys / Cold / Dental prosthetics / Ductility / Grain size / High-pressure and temperature / Humanities and Social Sciences / Industrial applications / Martensitic transformation / Mechanical properties / multidisciplinary / Plasticity / Science / Science (multidisciplinary) / Stress-strain curves / Temperature / Tensile strength / Titanium / Transformation-induced plasticity / Yield stress / ω phase