Li含量对轧制态Mg-3Al-1Zn合金组织及力学性能的影响

Effect of Li Content on Microstructure and Mechanical Properties of Rolled Mg-3Al-1Zn Alloy

利用光学显微镜、扫描电镜、万能实验机研究了Mg-3Al-1Zn-xLi(x=0、2、4、6)合金轧制板材的微观组织及力学性能。结果表明,添加Li元素后,可促进动态再结晶的进行,细化晶粒,同时合金的力学性能得到显著提高。当Li元素含量为4%时,合金的晶粒多数为细小的动态再结晶晶粒,合金的各项力学性能达到最佳,抗拉强度达到302MPa,伸长率达到12.6%。当Li元素含量达到6%后,晶粒变得粗大,合金板材的强度指标明显下降。

The microstructure and mechanical properties of rolled Mg-3Al-1Zn-xLi (x=0,2,4,6) alloy were analyzed by optical microscope,scanning electron microscope and universal testing machine.The results show that after adding Li elements,the dynamic recrystallization can be promoted,and then the grain is refined,and the mechanical properties of the alloy improve significantly.When the content of Li element is 4%,most of the alloy grain is small dynamic recrystallized grain, and the mechanical properties of the alloy are best,the tensile strength reaches 302 MPa,and the elongation percentage reaches 12.6%.When the content of Li element is 6%,the grain size becomes larger and the strength index of the alloy sheet decreases obviously.