MODELING OF THE TEXTURE TRANSFORMATION IN A TI-64 SHEET AFTER HOT COMPRESSION

Our aim was to investigate the mechanism of variant selection occurrin g in the phase transformation of a Ti-64 sheet after compression. For that purpose, a Ti-64 alloy sheet was 38% plastically deformed by comp ression in the beta field at 1050 degrees C. The ODF of the beta phase al high temperature was determined by an indirect method. Comparison between the experimental texture of the alpha phase at room temperatur e and a simulated texture calculated without variant selection from th e high temperature beta texture indicated that the phase transformatio n by cooling occurred with variant selection. By simulating the textur e change due to the beta-alpha transformation we showed that in a firs t approximation this variant selection can be related to the active sl ip systems involved in the plastic deformation of the beta matrix. (C) 1997 Acta Metallurgica Inc.