Texture Evolution and Phase Transformation in Titanium Investigated by In-Situ Neutron Diffraction

Abstract

We report in-situ neutron diffraction studies of texture evolution and the (hcp)↔(bcc) phase transformation in commercially pure cold-drawn titanium upon continuous heating and cooling, complemented by differential scanning calorimetry (DSC) measurements. We show that the recrystallization of the  phase at elevated temperature enhanced the preexisting fiber texture, which eventually facilitated the nucleation and growth of the  phase favored by the Burgers orientation relationship, i.e., {0001}//{110}. More strikingly, upon completion of the → transformation, the {110} texture (or preferred orientation) in  was eliminated immediately by the rapid grain growth of intergranular  allotriomorphs. This resulted in the loss of the original -texture when Ti was transformed back to from  to  upon subsequent cooling, distinct from the known texture memory effect for rolling textures in titanium. Our present work provides useful experimental results for understanding the mechanisms of texture evolution and phase transformation in titanium and its alloys and, by and large, low-symmetry alloys such as zirconium.