A polycrystal plasticity model was developed to analyze the room-temperature deformation behaviors of Mg-3A1-1Zn alloy（AZ31）.The uniaxial tension and compression tests at room temperature were conducted using cast a...A polycrystal plasticity model was developed to analyze the room-temperature deformation behaviors of Mg-3A1-1Zn alloy（AZ31）.The uniaxial tension and compression tests at room temperature were conducted using cast and extruded AZ31 rods with different textures and combined with the proposed model to reveal the deformation mechanisms.It is shown that,different flow curves of two specimens under tension and compression tests can be simulated by this model.The flow curves of AZ31 extrusions exhibit different shapes for tension and compression due to different activities of tensile twinning and pyramidalc＋a slip.The metallographic and TEM observations showed the equal twinning activities at the initial stage in tension and compression tests and the occurrence of pyramidalc＋a slip in compression of as-cast Mg-3A1-1Zn alloy with increasing the strain,which is consistent with the simulated results by the proposed model.展开更多
Samples of AZ80 alloy were hot extruded at 380 ℃ and aged at temperatures of 170 ℃ and 310 ℃ respectively for different periods to compare the effect of precipitate structures on the tensile-compressive yielding as...Samples of AZ80 alloy were hot extruded at 380 ℃ and aged at temperatures of 170 ℃ and 310 ℃ respectively for different periods to compare the effect of precipitate structures on the tensile-compressive yielding asymmetry in magnesium alloy. Uniaxial tension and compression along the extruded direction were carried out at room temperature. It was found that the yielding asymmetry in the aged samples was not as significant as that in the as-extruded samples. This was because twinning occurred less readily in the aged samples. And it was also confirmed by the fact that the increment of the critical resolved shear stress （CRSS） for twinning was higher and the Schmid factor was lower in the aged samples in the presence of precipitate. Thus, it was concluded that the yielding asymmetry could be reduced and even eliminated by increasing the area fraction of the precipitate phase.展开更多
基金Project(51201092)supported by the National Natural Science Foundation of China
文摘A polycrystal plasticity model was developed to analyze the room-temperature deformation behaviors of Mg-3A1-1Zn alloy（AZ31）.The uniaxial tension and compression tests at room temperature were conducted using cast and extruded AZ31 rods with different textures and combined with the proposed model to reveal the deformation mechanisms.It is shown that,different flow curves of two specimens under tension and compression tests can be simulated by this model.The flow curves of AZ31 extrusions exhibit different shapes for tension and compression due to different activities of tensile twinning and pyramidalc＋a slip.The metallographic and TEM observations showed the equal twinning activities at the initial stage in tension and compression tests and the occurrence of pyramidalc＋a slip in compression of as-cast Mg-3A1-1Zn alloy with increasing the strain,which is consistent with the simulated results by the proposed model.
基金Project (20110309) supported by the National Natural Science Foundation of China
文摘Samples of AZ80 alloy were hot extruded at 380 ℃ and aged at temperatures of 170 ℃ and 310 ℃ respectively for different periods to compare the effect of precipitate structures on the tensile-compressive yielding asymmetry in magnesium alloy. Uniaxial tension and compression along the extruded direction were carried out at room temperature. It was found that the yielding asymmetry in the aged samples was not as significant as that in the as-extruded samples. This was because twinning occurred less readily in the aged samples. And it was also confirmed by the fact that the increment of the critical resolved shear stress （CRSS） for twinning was higher and the Schmid factor was lower in the aged samples in the presence of precipitate. Thus, it was concluded that the yielding asymmetry could be reduced and even eliminated by increasing the area fraction of the precipitate phase.
