Effect of shear deformation on microstructure and texture evolution in commercially pure titanium

The role of shear strain and deformation temperature on the microstructure and texture evolution in commercially pure (CP) titanium was investigated in the present study. CP titanium samples were subjected to free-end torsion at elevated temperatures, starting from room temperature (298 K) to 873 K, for different shear strains of 0.5-2.5. Deformation twins of {10 (1) over bar2} type were observed in the samples deformed at lower temperatures (up to 673 K). Deformation bands were seen in some of the grains and the number of such grains was observed to be decreased with increasing the deformation temperature. Such deformation bands were observed to be facilitated prismatic slip at room temperature and basal slip at high temperatures. However, the presence of deformation twinning always favoured basal slip activity in twinned grains. Dynamically recrystallized grains were observed in the samples deformed at higher temperatures. The texture evolution in the samples was observed to be controlled mainly by activities of basal, prismatic and pyramidal <c + a> slips. Further, the ideal C-1 and C-2 fibres were found to be unstable during torsion of the samples and the ideal B fibres were observed in the samples deformed at a temperature of 873 K for a shear strain of 2.5.