Grain-structure development in heavily cold-rolled alpha-titanium

High-resolution electron back-scatter diffraction (EBSD) analysis was employed to establish mircostructure evolution in heavily cold-rolled alpha-titanium. After thickness reductions of 75% to 96%, significant microstructure and texture changes were documented. The surface area of high-angle grain boundaries was almost tripled, thus giving rise to an ultra-fine microstructure with a mean grain size of 0.6μm. Moreover, orientation spread around typical ‘split-basal’ rolling texture substantially increased. These effects were suggested to be related to the enhancement of pyramidal 〈c+a〉 slip.