Effect of erbium on microstructure and thermal compressing flow behavior of Mg-6Zn-0.5Zr alloy
(1.College of Science, Northeastern University, Shenyang 110004, China
2.辽宁省沈阳市东北大学理学院
3.The Key Laboratory of Electromagnetic Processing of Materials, Ministry of Education, Northeastern University, Shenyang 110004, China)
2.辽宁省沈阳市东北大学理学院
3.The Key Laboratory of Electromagnetic Processing of Materials, Ministry of Education, Northeastern University, Shenyang 110004, China)
Abstract: A series of thermal compressing tests of Mg-6Zn-0.5Zr and Mg-6Zn-0.5Zr-1Er alloys were performed on a Gleeble-1500D thermal simulator. The microstructures of thermal compressed Mg-6Zn-0.5Zr and Mg-6Zn-0.5Zr-1Er alloys were determined by optical microscopy, transmission electron microscopy and X-ray diffractometry. The results show that Mg-6Zn-0.5Zr alloy mainly consists of α-Mg and MgZn2 phase, while Mg-6Zn-0.5Zr-1Er alloy comprises α-Mg phase, coarse Mg3Zn4Er2 eutectic, rod-liked Mg3Zn4Er2 precipitated phase, fine I phase particle (Mg3Zn6Er, icosahedral quasicrystal structure). The peak flow stress becomes larger with increasing strain rate and erbium addition at the same temperature, and gets smaller with increasing deformation temperature at the same strain rate. The deformation activation energy increases with increasing temperature, strain rate and erbium addition. In addition, it is observed that the growth of dynamic recrystallization (DRX) grains of Mg-6Zn-0.5Zr-1Er alloy was markedly suppressed due to the pinning effect of fine I phase and Mg3Zn4Er2 phase during thermal compression.
Key words: Mg-6Zn-0.5Zr alloy; erbium; flow behavior; I phase; Mg3Zn4Er2 phase