Texture formation and transition in Cold-rolled titanium

Abstract

Rectangular bars of commercially pure titanium were cold rolled to various strains in the range 20%–80%. Optical and electron microscopy investigations reveal that at low strains titanium deforms mainly by twinning, whereas at strains above 40% it deforms solely by slip. Texture measurements indicate that the development of texture in titanium is rapid. At strains around 20% a split rolling direction texture forms. Further deformation from 20% to 40% leads to a texture transition from split rolling direction to split transverse direction. Short-term annealing of samples rolled to a strain of 40% causes texture transition from split transverse direction to split rolling direction. It also brings about recrystallization within the primary twins and an overall reduction in the density of dislocations. Twinning is believed to be responsible for the rapid development of texture and the transitions in texture. The formation of the stable end texture is thought to be due to slip.