A variant selection mechanism in the deformed and recrystallized matrix of a metastable -titanium alloy

摘要

The variant selection criteria during to phase transformations in a metastable -titanium alloy (Ti-5553) in the presence of deformation are examined. Two distinct metallurgical states in the matrix, heavily deformed and fully recrystallized, were obtained from a 90% cold-rolled alloy. The deformed and recrystallized samples were subjected to aging heat treatment for a short time to allow the precipitation of an intragranular phase. Electron backscattered diffraction was used to assess the crystallographic variant occurrence in the deformed as well as in the recrystallized grains. A discrete pole figure analysis revealed that a limited number of variants were evolved in the deformed grains while there was no variant selection in the recrystallized matrix. The results suggest that activation of {112}111 slip systems determines a strong variant selection in the plastically deformed matrix.