AZ80镁合金挤压方棒心部和表层的织构和力学性能

Texture and Mechanical Property Heterogeneities between the Center and the Outer Layer of Extruded AZ80 Magnesium Alloy Rectangular Bar

研究了截面尺寸为230mm×140mm的大型AZ80镁合金挤压方棒心部和表层的织构和力学性能差异。采用X射线衍射法(XRD)测定了心部和表层共4个位置的宏观织构。不同位置的全极图表明,尽管不同位置的织构都具有纤维织构的特征,但(0001)极和(1120)极的分布方式却彼此不同。通过拉伸应力-应变曲线研究了心部和表层ED(挤压方向)、TD(平行于230mm边)和ND(平行于140mm边)3个方向上的屈服行为。结果表明,无论心部还是表层,ED方向的屈服强度均远大于TD或ND方向的屈服强度,而TD和ND方向的屈服强度却相差无几;心部的ED、TD和ND屈服强度均稍大于表层对应方向的屈服强度。织构特征很好地解释了力学性能上的不均匀性。

Texture and tensile property heterogeneities between the center and the outer layer of extruded AZ80bar with 230mm×140mm cross-section were investigated.The macro-textures of the center and three locations of the outer layer were measured by X-ray diffraction(XRD)technique.Pole figures of these four positions show that although texture at different positions exhibits fibrous texture,distributions of(0001)and{1120}pole are different from each other.The yielding behaviors of ED,TDand NDsamples in the center and in the outer layer were investigated by stress-strain curves.The results reveal that:(1)in both the center and the outer layer,yield strength of EDdirection is much higher than that of TDor NDdirection,however,the difference between the yield strength of TDand NDcan be ignored;(2)the yield strength of the center in ED,TDand NDis slightly higher than yield strength of the outer in the corresponding direction.Tensile property heterogeneity can be well analyzed by the texture feature.