Variant selection and its effect on phase transformation textures in cold rolled titanium sheet

The recrystallization and phase transformation textures in cold rolled tita nium sheets with different rolling reductions have been investigated by mea ns of three dimensional crystallite orientation distribution function (CODF ) analysis, the high temperature X-ray diffraction (HTXRD) and transmission electron microscopy (TEM) technique. The formation of phase transformation texture is discussed in terms of orientation variant selection between alp ha and beta phases. It is found that at a low rolling reduction, for exampl e 30%, the transformation texture is composed of a more randomly distribute d orientations without orientation variant selection occurs. After titanium sheet cold rolled 80% and subsequently alpha --> beta --> alpha phase tran sformation, the main transformation textures is characterized by [(2) over bar 110]parallel to ND fibre texture due to orientation variant selection. (C) 2000 Elsevier Science S.A. All rights reserved.