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将从挤压棒材中截取的长轴与挤压方向分别成0°,45°和90°的AZ31镁合金长方体试样在中、高温度(523723 K)下沿长轴方向压缩变形,利用OM和SEM/EBSD技术观察和分析了初始取向对其微观织构演化的影响.结果表明,随着变形温度的降低,初始取向对变形行为的影响显著增加,在523 K时,长轴平行挤压方向的0°试样在ε=0.06时拉伸孪晶体积分数可达30%,随着应变量的增加,孪晶体积分数持续增加,在ε=0.3时达到90%;沿与棒材长轴夹角45°和90°截取的试样在ε=0.3时孪晶不足10%;拉伸孪晶的大量存在是0°试样出现急剧加工硬化的原因.0°试样变形至ε=0.2时几乎所有的晶粒都发牛了近90°的转动,基面由变形前平行于压缩方向转至与压缩方向垂直,45°试样只是在大应变时才发生晶粒的缓慢转动,而90°试样则几乎不发生晶粒转动.
The AZ31 magnesium alloy rectangular parallelepiped samples with the major axis and the extrusion direction of 0 °, 45 ° and 90 °, respectively, taken from the extruded bar were compressed and deformed along the long axis at medium and high temperature (523723 K) OM and SEM / EBSD techniques were used to observe and analyze the effect of initial orientation on the microstructure evolution. The results show that the initial orientation has a significant effect on the deformation behavior with the decrease of the deformation temperature. At 523 K, The volume fraction of twinned crystals at 0 ° in the direction of pressure was as high as 30% at ε = 0.06. With increasing strain, the volume fraction of twinned crystals increased continuously and reached 90% at ε = 0.3. The specimens with 45 ° and 90 ° included angle were less than 10% at ε = 0.3, and the presence of tensile twins was responsible for the sharp work hardening at 0 °. The specimens were deformed to ε = 0.2 almost all the grains are made of cattle nearly 90 ° rotation, the base by the deformation parallel to the direction of compression and compression perpendicular to the 45 ° sample only occurs in the large strain slow rotation of the grain , While the 90 ° sample is almost no grain rotation.