Microstructure Evolution of Commercial Pure Titanium During Interrupted In Situ Tensile Test

Abstract

Microstructure evolution of commercial pure titanium is investigated by interrupted in situ electron backscatter diffraction (EBSD) measurement during tensile deformation along transverse direction at room temperature. After 24 pct elongation, the split basal texture of initial material is weakened and rotated around 90 deg along normal direction (ND). \({{11}\bar{2}{{2}}}\)-\({{10}\bar{1}{{2}}}\) double twin is the main reason for the change of texture. The basal poles are rotated nearly perpendicular to ND by the primary \({{11}\bar{2}{{2}}}\) twin and back to ND through the reorientation of \({{10}\bar{1}{{2}}}\) secondary twin. Both Schmid factor criterion and displacement gradient accommodation are considered to predict the twin-induced texture evolution during TD tension. Kink bands formed by the accumulation of basal 〈a〉 dislocations are also observed in the deformed grain. The activation of other slip systems can deviate the rotation axis and reduce the rotation angle of kink boundary. Besides, the kink boundary with high basal dislocation density obviously hinders the twin transmission and simultaneously can be taken as a preferential nucleation site for \({{11}\bar{2}{{2}}}\) twin.