The microstructure evolution and its effect on flow stress of TC17 alloy during deformation in the α+β two-phase region were investigated via microstructure characterization and isothermal compression tests. Results...The microstructure evolution and its effect on flow stress of TC17 alloy during deformation in the α+β two-phase region were investigated via microstructure characterization and isothermal compression tests. Results showed that the spheroidized rate of α phase at 820 and 850℃ slightly increased with increasing strain. With increasing deformation temperature, the spheroidized rate of α phase showed a slight increasing trend, but the volume fraction of α phase significantly decreased. The flow stress at 780 ℃ and 1 s^-1 decreased continuously and steady state condition was not achieved up to strain of 1.2 due to dislocation annihilation and α lamellae rotation. Under this condition, the dynamic spheroidization was retarded. At the deformation temperatures of 820 and 850℃, and a strain rate of 1 s^-1, a steady state flow stress was observed at strains above 0.8 due to the balance between work hardening and dynamic softening. The dynamic softening was attributed to the α lamellae rotation, dynamic recovery and a little spheroidization.展开更多
基金Project(51575446)supported by the National Natural Science Foundation of ChinaProject(2017KJXX-27)supported by the Shaanxi Province Youth Science and Technology New Star Plan,ChinaProject(3102017AX003)supported by the Fundamental Research Funds for the Central Universities,China
文摘The microstructure evolution and its effect on flow stress of TC17 alloy during deformation in the α+β two-phase region were investigated via microstructure characterization and isothermal compression tests. Results showed that the spheroidized rate of α phase at 820 and 850℃ slightly increased with increasing strain. With increasing deformation temperature, the spheroidized rate of α phase showed a slight increasing trend, but the volume fraction of α phase significantly decreased. The flow stress at 780 ℃ and 1 s^-1 decreased continuously and steady state condition was not achieved up to strain of 1.2 due to dislocation annihilation and α lamellae rotation. Under this condition, the dynamic spheroidization was retarded. At the deformation temperatures of 820 and 850℃, and a strain rate of 1 s^-1, a steady state flow stress was observed at strains above 0.8 due to the balance between work hardening and dynamic softening. The dynamic softening was attributed to the α lamellae rotation, dynamic recovery and a little spheroidization.
