论文部分内容阅读
利用磁悬浮真空高频感应加热法熔炼高质量的镁锂合金,通过Si、Nd元素复合添加来研究其对Mg-11Li-3Al合金组织与力学性能的影响。结果表明:加入Si、Nd元素后,组织中主要生成Mg_2Si和Al_(11_Nd_3 2种第二相,其中Si的添加能够促使合金组织中形成篆体形貌的黑色析出物聚集区,而Nd的加入能够细化这种黑色棒状的析出物,并减小晶粒尺寸、洁净组织。当Nd的添加量为1%(质量分数)时其晶粒细化的效果最佳。经过XRD和EDS分析发现,这种黑色棒状的析出物为Mg_2Si相和Al_(11)Nd_3相的结合体。铸态合金的抗拉强度随着Si含量的增加递增,最后趋于稳定;其塑性并不会随某一种或是复合元素的添加而单调变化。实验得到了一种综合力学性能最佳的合金Mg-11Li-3Al-1Si-1Nd,其抗拉强度和伸长率分别为212.3 MPa和46.2%。
High-quality Mg-Li alloy was melted by high-frequency induction heating in maglev, and the effect of Si and Nd on microstructure and mechanical properties of Mg-11Li-3Al alloy was studied. The results show that after the addition of Si and Nd, the second phase of Mg_2Si and Al_ (11_Nd_3) are formed in the microstructure, and the addition of Si can promote the formation of black precipitates in the microstructure of the seal body, Refinement of this black rod-like precipitate, and the reduction of grain size, clean the organization.When Nd content of 1% (mass fraction), the grain refinement effect is the best.After XRD and EDS analysis found that, The black rod-like precipitates are a combination of Mg 2 Si phase and Al 11 Nd 3 phase.The tensile strength of as-cast alloy increases with the increasing of Si content and finally tends to be stable, and its plasticity does not change with the increase of Si content Or the monotonous changes of the composite elements.The experimental results show that the tensile strength and elongation of the alloy Mg-11Li-3Al-1Si-1Nd with the best mechanical properties are 212.3 MPa and 46.2% respectively.