摘要
以Zn-25Al-2.5Si合金为基体材料,通过常规铸造方法制备了不同稀土含量的锌铝合金。分析了稀土Nd对实验合金组织和力学性能的影响。结果表明,添加稀土后,在锌铝合金中,Nd与Al、Zn等形成复杂成分化合物,其硬度高,热硬性好,分散于晶界和枝晶中,细化了组织,且有效地阻碍了高温时基体的变形和晶界移动。Nd使合金力学性能得到提高,尤其高温强度和硬度提高显著。其中添加0.8 wt%Nd的合金综合性能最好,180℃时的抗拉强度提高48.8%,硬度提高67.4%。
Based on Zn-25Al-2.5Si alloy the Zn-Al alloys containing different content of rare earth element Nd were prepared. The effects of Nd on the microstructure and mechanical properties of Zn- 25Al-2.5Si alloys were studied. The result shows that Nd can react with Al, Zn etc. to form some complex compounds which have high hardness and good stability of hardness at elevated temperature. When the complex compounds disperse at grain boundary or at the dendrite crystal interfaces, the alloy has been enhanced and deformation of matrix and movement of grain boundary at high temperature are retarded. Thus improves mechanical properties, especially the tensile strength and micro-hardness at high temperature. The optimization of microstructure and performance was obtained with 0. 8% （wt） Nd addition. The tensile strength of alloy can be increased by 48.8 % and by 67.4 % in micro-hardness at 180 ℃.
出处
《铸造技术》
CAS
北大核心
2010年第4期458-461,共4页
Foundry Technology
关键词
锌铝合金
稀土
显微组织
力学性能
Zn-Al alloy
Rare earth
Microstructure
Mechanical property
