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

Abstract 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 wphase 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 w-titanium with a chemical composition of commercially pure titanium grade 4 and an average grain size of 3.4 mm. We observed that stress-induced w → α martensitic phase transformation occurs exclusively in the plastic regime. As plastic deformation proceeds, the volume fraction of a-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. These mechanical properties are comparable to those of a titanium alloy Ti-6Al-4V. The present study revealed transformation-induced plasticity in bulk polycrystalline w-titanium.