Effect of Rolling on Texture Evolution and Recrystallization of Polycrystalline Tantalum

Polycrystalline tantalum sheets have been deformed through room-temperature rolling (RTR), accumulative pack-rolling (APR), and cryogenic-rolling (CR), respectively. The fraction of α-texture in the APR-ed samples was relatively higher, while the fraction of γ-texture was slightly lower. The rolled samples have similar microstructure and average grain size regardless of the rolling methods. After annealing at 900°C for 30 min, the recrystallization in the cryogenically rolled samples occurred much more easily, and the average grain size of the samples was 2.5 times larger than that of the room-temperature-rolled samples. With the increasing of annealing time, the fraction of the α-texture in the APR-ed samples decreased dramatically. According to the calculation of the stored energy, cryogenically-rolled samples contained a high dislocation density and stored energy, with values of 11.70 × 1015/m2 and 1.32 J/g, respectively, which could be contributing to its recrystallization during annealing. These findings are of great help in developing polycrystalline tantalum sheets with fine grains.