Metals | |
Microstructure Evolution of a High Nb Containing TiAl Alloy with (α2 + γ) Microstructure during Elevated Temperature Deformation | |
Jinshan Li1  Yan Liu1  Bin Tang1  Hongchao Kou1  Yudong Chu1  Lei Zhu1  | |
[1] State Key Laboratory of Solidification Processing, Northwestern Polytechnical University, Xi’an 710072, China; | |
关键词: titanium aluminides; isothermal compression; microstructure; texture; hot deformation mechanism; | |
DOI : 10.3390/met8110916 | |
来源: DOAJ |
【 摘 要 】
In order to verify the correctness of the transition of deformation mechanism with the change in deformation parameters and to reveal the types and mechanism of dynamic recrystallization of γ grains during compression deformation, microstructure characterization of Ti-43.5Al-8Nb-0.2W-0.2B (at. %) alloy after isothermal compression deformation were performed. When the alloy was deformed at 1000 °C/10−2 s−1, the initial γ grains are elongated and significantly refined and the fraction of low angle grain boundaries (LAGB) of γ grains is obviously increased and the texture intensity remains unchanged, which indicates that the compression deformation in dislocation creep region is dominated by intragranular deformation and dynamic recrystallization (DRX) of γ grains. Besides, the lattice rotation at grain boundary serrations may be responsible for the nucleation of new recrystallized γ grains, and the following growth process may be achieved by the migration of γ grain boundaries. However, when the alloy deformed at 1050 °C/10−4 s−1 and 1000 °C/10−4 s−1, the γ grains maintain equiaxed shapes and distribute more uniformly and the fraction of LAGB of γ grains is slightly raised and the texture sharpness decreases, which indicates that the compression deformation in grain boundary sliding (GBS) region is mainly controlled by GBS of γ grains and DRX occurs simultaneously within some coarse γ grains.
【 授权许可】
Unknown