Texture control and the anisotropy of mechanical properties in titanium sheet

By means of three-dimensional crystallite orientation distribution function (CODF) analysis, the relationship between texture control processes and mechanical properties anisotropy in titanium sheet has been investigated. The formation and transition of cold-rolling texture, recrystallization texture and phase transformation texture are also discussed. The results show that, after being cold rolled unidirectionally and annealed, titanium sheet exhibits a strong anisotropy of mechanical properties due to the pyramidal textures (2 1 1 5) [0 1 1 ] and (1 0 1 3) [1 2 1 0]. After a cyclic phase transformation process coupled with cold rolling and annealing treatment, the recrystallization texture component (1 0 1 3) [1 2 1 0] is suppressed and [h k i l] 9∥ND transformation fibre texture (where ND is the sheet normal direction) are developed, which produce a well improved mechanical anisotropy. The cross-rolling process can create a basal type texture (0 0 0 2) 〈u v t w〉 or a near basal type texture, which leads to low level planar mechanical properties anisotropy but to relatively high normal plastic anisotropy (R value).