工业纯钛TA1的双道次热压缩变形及软化行为

在Gleeble-3500热模拟试验机上对工业纯钛TA1进行单、双道次等温热压缩试验,变形温度为650~850 ℃,道次间隙时间为1~60 s,变形速率为10 s^-1,研究了工业纯钛TA1单、双道次热压缩过程中静态软化和动态软化行为。利用光学显微镜对变形后的微观组织进行观察,研究了工业纯钛TA1在不同变形条件下的微观组织演变。结果表明,工业纯钛TA1在单、双道次热压缩变形过程中表现出明显的硬化和软化行为,峰值应力前表现为加工硬化,峰值应力后表现为加工软化,最终达到动态软化和加工硬化的动态平衡。在道次间隙时间内发生静态软化,静态软化程度随着道次间隙时间的增加和温度的升高而增大。随着道次间隙时间的延长和温度的升高,道次间再结晶更加充分,第二道次变形后晶粒尺寸增加更明显,当发生完全再结晶时,软化程度达到最大。在热压缩变形期间,发生动态软化,650 ℃和750 ℃时以动态再结晶为主,850 ℃时以动态回复为主。

Two-pass hot compression deformation and softening behavior of commercially pure titanium TA1

Commercially pure titanium TA1 was subjected to one-pass and two-pass hot compression experiments on Gleeble-3500 thermal simulator with deformation temperature of 650-850 ℃, the pass interval time of 1-60 s, and the deformation rate of 10 s^-1. The static and dynamic softening behaviors of the commercially pure titanium TA1 during the one-pass and two-pass hot compression were studied. The microstructure evolution of the commercially pure titanium TA1 under different deformation conditions was studied by optical microscope. The results show that the hardening and softening behaviors of the commercially pure titanium TA1 is obvious during both the one-pass and the two-pass hot compression deformation. Before the peak stress, it is work hardening, and after the peak stress, it is work softening. Finally, the dynamic softening and work hardening reach the dynamic equilibrium. The static softening occurs in the interval time. The static softening rate increases with the increase of interval time as well as the temperature. The recrystallization between passes becomes more sufficient, and the grains grow up obviously after the second pass deformation with the increase of interval time and temperature. When complete recrystallization occurs, the softening rate reaches the maximum. During the hot compression deformation, dynamic softening occurs. Dynamic recrystallization is dominated at 650 ℃ and 750 ℃ and dynamic recovery at 850 ℃.