Tuning recrystallization texture via two-step pre-recovery for cold rolled pure tantalum sheet

Two-step pre-recovery processes followed by recrystallization annealing were designed to regulate the recrystallization textures for the pure tantalum sheet. The results show that the directly recrystallized microstructure has a strong γ fiber. The fraction of α fiber comparable to that of γ fiber in the recrystallized microstructures with fine grains and a higher recrystallized fraction can be achieved by the two-step pre-recovery at lower or higher temperatures for relatively short time followed by recrystallization annealing. The fraction of γ fiber increases in the recrystallized microstructures after pre-recovery at lower temperatures for shorter or intermediate time or at intermediate temperatures, due to the retarded recrystallization of the α-oriented grains and thus the distinct advantage in the evolution of recrystallized grains for the γ-oriented grains. The two-step pre-recovery at lower temperatures for much longer time also leads to an obviously increased fraction of γ fiber in the recrystallized microstructure, which is closely related to the size advantage of the γ-oriented recrystallized grains.