On tension–compression yield asymmetry in an extruded Mg–3Al–1Zn alloy
On tension–compression yield asymmetry in an extruded Mg–3Al–1Zn alloy
复制标题
DOI：
10.1016/j.jallcom.2008.12.033
复制
发表时间：
2009-06
影响因子：
6.2
通讯作者：
D. Yin;J. Wang;J. Liu;Xiang Zhao
中科院分区：
文献类型：
--
作者：
D. Yin;J. Wang;J. Liu;Xiang Zhao
通过改变载荷方向和晶粒尺寸，研究了挤压态Mg-3Al-1 Zn合金的室温拉伸-压缩屈服不对称性。提出了变形模式激活的判据，分析了载荷方向对孪生活动的影响。当载荷角为45°时，拉压后的双晶面积分数相似，压缩屈服应力与拉伸屈服应力的对应比等于1.02。当载荷方向与挤压轴平行或垂直时，拉伸和压缩时的屈服应力和孪晶活动明显不同，导致拉伸-压缩屈服不对称。晶粒粗化虽然促进了沿着挤压轴的拉伸孪晶，但并不能降低屈服不对称性。此外，基于孪晶面积分数的定量统计，评价了屈服变形过程中孪晶对应变的贡献。
The tension–compression yield asymmetry of an extruded Mg–3Al–1Zn alloy was examined by changing load directions and grain sizes in room-temperature mechanical tests. A criterion for the activation of deformation modes was proposed to analyze the effect of load direction on twinning activity. When the load angle was 45°, the twin area fractions after tension and compression resembled each other, and the corresponding ratio between compression yield stress and tension yield stress equaled 1.02. As the load direction was parallel or perpendicular to the extrusion axis, the yield stress and twinning activity in tension differed obviously from those in compression, resulting in marked tension–compression yield asymmetry. Although grain-coarsening promotes twinning in tension along extrusion axis, it cannot reduce the yield asymmetry. Further, the contributions of twinning to strain during yield deformation were evaluated based on the quantitative statistic of twin area fraction.