This study aimed to investigate dynamic recrystallization (DRX) behavior during compression of magnesium alloy AZ31. Cylinder samples were cut from the extruded rod and hot rolled sheet AZ31 for compression test. The ...This study aimed to investigate dynamic recrystallization (DRX) behavior during compression of magnesium alloy AZ31. Cylinder samples were cut from the extruded rod and hot rolled sheet AZ31 for compression test. The samples were compressed using a Gleeble 1500D at a temperature of 300℃ and a strain rate of 0.01 s-1. Grain orientations and misorientation angles across grain boundaries for the tested samples were obtained by using electron backscatter diffraction (EBSD) technique. The results showed that strong basal texture was observed after 50% compression (ε = 0.69) on both the extruded and hot rolled samples, which have different initial textures. It was observed that with increased strain, DRX grains gradually rotated to basal orientation, and grain boundaries with misorientation angle of near 30° was formed in the samples. At the strain of 0.69, a high fraction of high-angle (> 60°) bounda-ries was present in the extruded sample, whereas almost no high angle boundaries were observed in the hot rolled sheet sample.展开更多
Experiments were conducted to evaluate the effects of extrusion ratio on the microstructure and texture developments of AZ31 Mg alloy during forward extrusion.The forward extrusion was undertaken at 400°C with ex...Experiments were conducted to evaluate the effects of extrusion ratio on the microstructure and texture developments of AZ31 Mg alloy during forward extrusion.The forward extrusion was undertaken at 400°C with extrusion ratios of 10,18,and 25 after the alloy was homogenized at 410°C for 12 h.Partially recrystallized microstructures were observed in all the extruded rods examined.The texture of the large elongated deformed grains appeared strongly centered at 1010 dominating the extrusion texture,while the recrystallized grains exhibited much more randomized texture.For the alloy with the largest ER(25),coarse secondary recrystallized grains were found which presented a different texture component with-11 2 0-parallel to the ED.The occurrence of the coarse secondary recrystallized grains in the alloy with the largest ER might be attributed to that the large ER raised the die exit temperature during extrusion and thus promoted significantly grain growth after the extruded rod exited from extrusion die.The intensities of different texture components varied with ER because ER affected the contents of the deformed grains,DRX grains and coarse secondary recrystallized grains.In particular,the maximum intensity of fiber texture was decreased as ER increased due to the decrease of the large elongated deformed grains.展开更多
基金Supported by the National Basic Research Program of China ("973" Project) (Grant No. 2007CB613703)the International Key Program for Cooperation in Science and Technology of China (Grant No. 2006DFA51160)the Natural Science Founda-tion of China (Grant Nos. 50571049, 50231030)
文摘This study aimed to investigate dynamic recrystallization (DRX) behavior during compression of magnesium alloy AZ31. Cylinder samples were cut from the extruded rod and hot rolled sheet AZ31 for compression test. The samples were compressed using a Gleeble 1500D at a temperature of 300℃ and a strain rate of 0.01 s-1. Grain orientations and misorientation angles across grain boundaries for the tested samples were obtained by using electron backscatter diffraction (EBSD) technique. The results showed that strong basal texture was observed after 50% compression (ε = 0.69) on both the extruded and hot rolled samples, which have different initial textures. It was observed that with increased strain, DRX grains gradually rotated to basal orientation, and grain boundaries with misorientation angle of near 30° was formed in the samples. At the strain of 0.69, a high fraction of high-angle (> 60°) bounda-ries was present in the extruded sample, whereas almost no high angle boundaries were observed in the hot rolled sheet sample.
基金supported by the National Basic Research Program of China ("973" Project) (Grant No. 2007CB613703)the National Natural Science Foundation of China (Grant No. 50890172)the Fundamental Research Funds for the Central Universities (Grant No. CDJXS11132227)
文摘Experiments were conducted to evaluate the effects of extrusion ratio on the microstructure and texture developments of AZ31 Mg alloy during forward extrusion.The forward extrusion was undertaken at 400°C with extrusion ratios of 10,18,and 25 after the alloy was homogenized at 410°C for 12 h.Partially recrystallized microstructures were observed in all the extruded rods examined.The texture of the large elongated deformed grains appeared strongly centered at 1010 dominating the extrusion texture,while the recrystallized grains exhibited much more randomized texture.For the alloy with the largest ER(25),coarse secondary recrystallized grains were found which presented a different texture component with-11 2 0-parallel to the ED.The occurrence of the coarse secondary recrystallized grains in the alloy with the largest ER might be attributed to that the large ER raised the die exit temperature during extrusion and thus promoted significantly grain growth after the extruded rod exited from extrusion die.The intensities of different texture components varied with ER because ER affected the contents of the deformed grains,DRX grains and coarse secondary recrystallized grains.In particular,the maximum intensity of fiber texture was decreased as ER increased due to the decrease of the large elongated deformed grains.
