Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
1575690 | Materials Science and Engineering: A | 2014 | 11 Pages |
Abstract
In order to evaluate the dynamic recrystallization (DRX) behavior of as-cast Ti-6Al-2Zr-1Mo-1V alloy, a series of compressions with a height reduction of 60% were performed in a temperature range of 1073-1323 K (0.55-0.68Tm) and a strain rate range of 0.01-10 sâ1 on a Gleeble1500 thermo-mechanical simulator. By the regression analysis for conventional hyperbolic sine equation, the activation energy of DRX was determined as Q=933.3233 kJ molâ1, and a dimensionless parameter controlling the stored energy were determined as Z/A=εÌexp[(933.3233Ã103)/8.31T]/6.17726Ã1036. According to the strain hardening rate curves (dÏ/dε versus Ï), three characteristic parameters including the critical strain for DRX initiation (εc), the strain for peak stress (εp), and the strain for maximum softening rate (εâ) were identified. A modified Avrami type equation XDRX=1âexp{â[(εâεc/εâ)]m} was introduced to characterize the evolution of DRX volume fraction in α-phase temperatures under 0.59Tm, in which εc, εâ and m were described as εc=0.028774(Z/A)0.04665,εâ=0.45379(Z/A)â6.118274e-4 and m=4.133402 respectively. The evolution of DRX volume was described as the following: for a fixed strain rate, the strain required for the same amount of DRX volume fraction increases with decreasing deformation temperature, in contrast, for a fixed temperature, it increases with increasing strain rate. Finally, the theoretical predictions were validated by the microstructure graphs.
Related Topics
Physical Sciences and Engineering
Materials Science
Materials Science (General)
Authors
Guo-zheng Quan, Dong-sen Wu, Gui-chang Luo, Yu-feng Xia, Jie Zhou, Qing Liu, Lin Gao,