Multi-pass hot processing methods are commonly used in magnesium(Mg)alloys to overcome the poor workability due to limited slip systems,which generally involve complicated post-deformation softening and hardening beha...Multi-pass hot processing methods are commonly used in magnesium(Mg)alloys to overcome the poor workability due to limited slip systems,which generally involve complicated post-deformation softening and hardening behaviors.In this work,to reveal post-deformation softening and hardening mechanisms of a Mg-2Y-1Zn alloy,double-stage hot compression tests and microstructural observations were conducted.The results showed that the softening fraction of Mg-2Y-1Zn alloy showed a non-linear dependence on deformation conditions and could be general coupled by Z parameter.Due to the formation and cross-overlapping of twins and kinks,only static recovery(SRV)occurred during holding process at 300℃/0.001 s^(-1) which led to the least static softening:5.52% after 10 s of holding.For samples at 400℃/0.001s^(-1),the enhanced post-deformation softening,which is 11.93% after 10 s of holding,was attributed to static recrystallization(SRX)followed continuous dynamic recrystallization(CDRX)happened during first deformation stage as well as SRV influenced by the LPSO phases.Under deformation condition of 400℃/0.1 s^(-1),the coupled meta-dynamic recrystallization(MDRX)and SRX resulted in serious stress relaxation,which is 42.83% after 10 s of holding,and caused hardening phenomenon at reloading stage.The 18R-LPSO and 14H-LPSO phases synchronously worked on deformation behaviors and limited the growth of recrystallized grains.Further,a simplified static softening kinetics model was established based on Johnson-Mehl-Avrami-Kolmogorov equation and employed to rationalize experimental data.展开更多
基金supported by the National Natural Science Foundation of China(52174361,52074114)Science and Technology Innovation Program of Hunan Province(2023RC3106)+2 种基金Open Fund of the China Spallation Neutron Source Songshan Lake Science City(KFKT2023B13)Graduate Training and Innovation Practice Base of Hunan Province,China Scholarship Council(202106130051)Postgraduate Scientific Research Innovation Project of Hunan Province(QL20220100,QL20230094).
文摘Multi-pass hot processing methods are commonly used in magnesium(Mg)alloys to overcome the poor workability due to limited slip systems,which generally involve complicated post-deformation softening and hardening behaviors.In this work,to reveal post-deformation softening and hardening mechanisms of a Mg-2Y-1Zn alloy,double-stage hot compression tests and microstructural observations were conducted.The results showed that the softening fraction of Mg-2Y-1Zn alloy showed a non-linear dependence on deformation conditions and could be general coupled by Z parameter.Due to the formation and cross-overlapping of twins and kinks,only static recovery(SRV)occurred during holding process at 300℃/0.001 s^(-1) which led to the least static softening:5.52% after 10 s of holding.For samples at 400℃/0.001s^(-1),the enhanced post-deformation softening,which is 11.93% after 10 s of holding,was attributed to static recrystallization(SRX)followed continuous dynamic recrystallization(CDRX)happened during first deformation stage as well as SRV influenced by the LPSO phases.Under deformation condition of 400℃/0.1 s^(-1),the coupled meta-dynamic recrystallization(MDRX)and SRX resulted in serious stress relaxation,which is 42.83% after 10 s of holding,and caused hardening phenomenon at reloading stage.The 18R-LPSO and 14H-LPSO phases synchronously worked on deformation behaviors and limited the growth of recrystallized grains.Further,a simplified static softening kinetics model was established based on Johnson-Mehl-Avrami-Kolmogorov equation and employed to rationalize experimental data.
