稀土La对2024铝合金铸态组织的影响

制备了稀土La添加量分别为0、0.1%、0.2%、0.3%的2024铝合金, 通过X射线衍射、金相、扫描显微组织分析和力学性能测试, 研究了La对2024铝合金铸态组织与性能的影响。研究结果表明 随着La的添加, 2024铝合金铸态组织逐渐细化, 当La添加量为0.2%时, 铸态晶粒尺寸达到80 μm；当继续提高La添加量时, 合金的铸态组织会逐渐粗化；La的添加在2024铝合金中生成了第二相, 并以化合物的形式在晶界处存在。

Effect of Lanthanum on As-cast Microstructure of 2024 Aluminum Alloy

Four types of 2024 aluminum alloy as samples were prepared with La addition at 0, 0.1%, 0.2% and 0.3%, and influences of La on as-cast microstructure and properties of 2024 aluminum alloy were investigated by X-ray diffraction, optical microscopy, scanning electron microscopy and mechanical property testing. The results showed that, owing to La addition, a refinement of as-cast microstructure was observed. When the amount of La attains 0.2%, the as-cast grain reaches 80 μm. Yet, the as-cast microstructure of alloy coarsens gradually when La exceeds 0.2%. In the presence of La, the second-phase compounds generate along the grain boundary of 2024 aluminum alloys.