Effect of dislocation channeling and kink band formation on enhanced tensile properties of a new beta Ti alloy

Tensile properties and deformation mechanisms of a newly developed beta Ti alloy, Ti-3Al-8Mo-7V-3Cr (wt.%), were investigated at room temperature. The alloy was found to exhibit a yield point at high strength level of 920 MPa and excellent total elongation of 31%. The yield point was presumably caused by the oxygen in the alloy, although the nano-sized omega precipitates were present, too. The examinations of deformed microstructures at different strains using transmission electron microscope and electron backscatter diffraction showed that during straining dislocation glide occurred in narrow channels and kink bands were formed leading to a high ductility. The competing effect of strain hardening by intersecting of channels and twins and softening by kink band formation results in a flat plateau-type engineering stress-strain curve. (C) 2019 Elsevier B.V. All rights reserved.