摘要镁合金具有拉压屈服不对称性,其拉伸屈服强度高于压缩屈服强度,此现象对于镁合金的使用性能有重要的意义。实验以挤压态ZK60镁合金为对象从孪晶与织构的影响入手,以塑性变形机理为出发点。对挤压态ZK60镁合金棒材进行金相观察、TEM与织构衍射实验分析其微观结构特点(显微晶相、第二相形态与织构分布),同时通过对比拉伸与压缩的金相图和镁合金的极图,并结合在相关的研究背景,综合讨论了孪晶与织构对镁合金拉伸与压缩屈服不对称性的影响。9207
本实验发现孪晶的比例造成了镁合金的拉压屈服不对称。晶粒的{0001}与{101(_)0}基面和挤压方向平行,压缩时压应力分量垂直于c轴易发生{10-12}孪晶造成压缩屈服强度较低。
关键词 镁合金;拉压屈服不对称性;孪晶;织构;
毕业设计说明书(论文)外文摘要
Title Tensile compressive yield asymmetry of extruded ZK60 Mg alloy
Abstract
Magnesium alloy shows the asymmetry of the tensile and compressive yield strength. The tensile yield strength is higher than the compressive. The phenomenon is important for the application of magnesium alloy. We study on the extruded ZK60 magnesium alloy. Especially research on the principle of the plastic deformation. To analyze micro-structural features of the Extruded ZK60 Magnesium Alloy Rods, we did metallographic observations, the TEM and texture diffraction experiments (Microscopic crystalline phase, second phase forms and texture distribution). By contrasting tensile and compression of the phase diagram and the pole figure of magnesium alloy, we discuss how the twinning and texture affect the Asymmetric of the Magnesium alloy tensile and compressive yield strength.
At last, we find the percentage of the twinning must be the major factors. The {0001} and {10-10} Base Surface is parallel to the extruded direction, and the compressive stress is perpendicular to the c axle. As the result, it tends to actuate the {10-12} Twinning. So the compressive yield strength is the lower.
Keyword Magnesium alloy; Tension and compression yield asymmetry;Twinning;Texture
目 次