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-lEr alloys...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-lEr 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 a-Mg and MgZn2 phase, while Mg-6Zn-0.5Zr-1Er alloy comprises a-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.展开更多
基金Project(2003AA331110) supported by the High-Tech Research and Development Program of China
文摘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-lEr 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 a-Mg and MgZn2 phase, while Mg-6Zn-0.5Zr-1Er alloy comprises a-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.
