Modeling the transformation texture of Ti-64 sheets after rolling in the beta-field

The variant selection occurring in the beta-alpha phase transformation of Ti-64 material after rolling in the beta-field was investigated by using texture transformation modelings. In a previous work published in this journal, we observed that the variant selection was very sensitive to the deformation degree imposed at high temperature prior to the transformation. In this contribution, we assumed that crystal defects formed during glides on the {110}[111] and {112}[111] beta Slip systems could favor the growth of plates corresponding to specific variants. Moreover, a detailed study of the beta --> alpha phase transformation suggested a link between the selected variants and the slip systems activated at high temperature. Therefore, we developed a texture transformation modeling, assuming that a variant is selected if its corresponding slip system was sufficiently activated in the last step of the hot deformation. The activity of the slip systems was evaluated by a rate sensitive Taylor model. The modeling was applied to a Ti-64 material 75% rolled at 1050 degrees C and the simulated texture was in good agreement with the experimental one. (C) 1997 Elsevier Science S.A.