Development of the Rolling Texture in Titanium

Abstract

The complete ODF of titanium, cold rolled up to 80% deformation, was calculated using the series expansion method, including the zero range method. The rolling texture obtained after 80% deformation is mainly characterized by the well-known orientation {0001}〈101¯0〉 ± 40°TD but with distinct spread ranges about it. At about 40% deformation several other texture components are found of which the component {0001}〈112¯0〉 must be mentioned. Further features of the obtained textures are a minor component as well as characteristic zero ranges. Texture development as function of the rolling degree can be divided into three ranges judged by increase or decrease of various texture components. In the early stages twinning in two different types of twinning systems is assumed whereas at higher deformation degrees the formation of the rolling texture is ascribed to glide deformation only.

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

“…7c). This perhaps evidences suppression of twinning at large rolling strains and agrees well with findings in the literature [3][4][5][6]9,10].…”

“…2c). In agreement with findings in the literature [3][4][5][6][7][8][9][10]17,18], twinning seemed to be suppressed at this level of reduction. In addition, the twin boundaries were almost completely transformed into HABs with misorientations different from those associated with twinning (Fig.…”

“…Microstructure evolution at relatively low and intermediate strains (r75%) was found to be in good agreement with prior observations [3][4][5][6][7][8][9][10]. At low strains, microstructure evolution was dominated by the development of f1122g〈112 3〉 compressive and f1012g〈101 1〉 tensile twins which rapidly refined the grain size.…”

“…6b and c). This is also an expected result [6][7][8][9][10]; this texture is believed to be stable during rolling and originates from a balance between twinning, prism slip, and 〈c þa〉 slip [9]. Formation of this texture is thought to contribute (at least partially) to the rapid drop of the strain hardening rate observed in this strain range (Fig.…”

“…At relatively large thickness reductions (Z40%), grain refinement suppresses twinning activity, and slip becomes the dominant deformation mode [9,10]. Microstructure formation at these large strains has been hypothesized to be largely controlled by the development of deformation-induced dislocation boundaries [5,8], but the details of this process are not clear.…”