Behavior of Sheets from Ti-alloys by Rolling and Heat Treatment

Sheets from single-and two-phase Ti-alloys (VT1-0, Ti-22Nb-9%Zr and VT-16) were rolled at the room temperature up to various deformation degrees and annealed at temperatures 500-900 degrees C. The regularities of texture formation in both phases were established. In the technically pure Ti (VT1-0) with the single alpha-Ti phase the final stable texture component is (0001)+/- 30-40 degrees ND-TD<10<(1)over bar>0>. In the two-phase alloy the reorientation of basal axes of alpha-Ti occurs by the same trajectories as in the single phase alloy. However, in the case of two-phase alloy texture development in alpha-Ti stops at the intermediate stage, when this texture consists of components with rolling planes (0001)+/- 15-20 degrees ND-RD and (0001)+/- 30-40 degrees ND-TD. The stability of the first components can be provided both by the mutually balanced operation of pyramidal and basal slip systems, activity of which remains at the high deformation degree of two-phase alloy, and by the dynamic alpha <->beta phase transformations, taking place in the distorted structures of alpha- and beta-phases in the course of its cold rolling. At recrystallization of technically pure Ti the basal component disappears in its texture. At the same time, prismatic axes turn by angles 20 divided by 30 degrees depending on the heating rate of the rolled sheet and annealing temperature. At recrystallization of the two-phase Ti-alloy prismatic axes of its a-grains doesn't turn relative to their positions in the rolling texture, as it occurs in the single-phase alloy. This fact indicates to some alternative mode of arising new recrystallized grains in two-phase alloys.