In situ observation of texture evolution during a ! b and b ! a phase transformations in titanium alloys investigated by neutron diffraction

Texture changes during recrystallization and the a–b–a phase transformation in two titanium alloys were investigated in situ by timeof-flight neutron diffraction by heating in a vacuum furnace to 950 C. In commercially pure titanium, a strong texture memory effect is observed. This effect is a direct consequence of an orientation-selective a ! b transformation, favoring new orientations produced during nucleation and grain growth. The b–a transformation favors b orientations with minimal misorientations, resulting in a strong final a texture that emphasizes the grain growth component. In Ti–6Al–4V, the texture memory effect is less pronounced. The high-temperature b texture is obtained by growth of pre-existing b nuclei. In a similar way, during cooling, the growth of a domains is controlled by hightemperature a orientations inherited from the b grains with Burgers orientation relation. 2007 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.