Unique texture transition during sub beta-transus annealing of warm-rolled Ti-6Al-4V alloy: Role of orientation dependent spheroidization

We report here, interrelation between orientation dependent spheroidization [1] and bulk texture evolution during static annealing of warm-rolled Ti-6Al-4V alloy. Weakening of basal fibre (ND parallel to < 0001 >) and complementary strengthening of prism fibre (RD parallel to < 10 (1) over bar0 >) occur on annealing, which is unique and contrary to previous reports. Texture transition is conjugated with two counteracting processes, both being alpha-colony orientation dependent: spheroidization of alpha(P)-phase increasing spread of the fibres, and variant selection during alpha(P) -> beta -> alpha(s) transformation strengthening only the prism fibre. Basal fibre weakens from orientation dependent spheroidization on annealing, while prism fibre intensity is maintained or increased from alpha(s) selection depending on annealing durations. (C) 2018 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.