Evolution of dislocation boundaries during cold deformation of microcrystalline titanium

Abstract

The evolution of the misorientation spectrum of titanium during cold deformation via uniaxial tension was analyzed. The initial stage of plastic flow (true strain e ∼ 0.1) is characterized by the intense formation of low-angle boundaries (LABs). The axes of rotation of most LABs are close to 〈001〉. This fact can be treated as a consequence of predominant prismatic slip during plastic deformation of titanium. An increase in strain to e ∼ 0.5 and ∼ 1.0 is accompanied by both a gradual increase in the mean misorientation angle of LABs and an increase in the fraction of high-angle boundaries (HABs). Twinning occurs over the entire deformation range under study: twinning on the {112}〈\(\overline 1 \overline 1 \)3〉 system is predominant at the initial stage, and twinning on the {102}〈\(\overline 2 \overline 1 \)3〉 system is predominant at the final stage. It is found that the misorientation spectrum of HABs forming during deformation is dominated by 15°, 30°, and 90° boundaries.