The Deformation Behavior of Oxygen-Modified Ti-29Nb-13Ta-4.6Zr(wt.%)

¹ Department of Mechanical Engineering, Michigan State University, East Lansing, MI 48824, USA
² Department of Chemical Engineering and Materials Science, Michigan State University, East Lansing, MI 48824, USA
³ Joining and Welding Research Institute, Osaka University, 11-1, Mihogaoka, Ibaraki, Osaka, 567-0047, Japan
⁴ Department of Mechanical Engineering, Faculty of Science and Engineering, Kindai University, Higashiosaka 577-8502, Japan
⁵ Institute for Materials Research, Tohoku University, Sendai 980-8577, Japan

^* Corresponding author email: boehlert@egr.msu.edu

Abstract

A series of Ti-29Nb-13Ta-4.6Zr(wt.%) {TNTZ} alloys containing either 0.1, 0.3 or 0.7(wt.%) oxygen (O) were room-temperature tensile tested inside a scanning electron microscope to evaluate the effect of O on the deformation evolution. The deformation modes observed for TNTZ-0.1O, which exhibited the largest elongation-to-failure and lowest strength of all the alloys, were deformation-induced α”-martensitic transformation, {332}<113> twinning, and <111> slip. For the other two alloys, <111> slip was the dominant deformation mode, where TNTZ-0.7O exhibited more homogeneous and extensive slip, a higher frequency of cross slip, and a higher work-hardening rate, all of which contributed to both its strength and elongation-to-failure being greater than that for TNTZ-0.3O. TNTZ-0.3O exhibited the greatest tendency for cracking, which generally occurred on grain boundaries perpendicular to the tensile axis, leading to the lowest elongation-to-failure of all the alloys.