中文摘要：

利用显微硬度、TEM、HREM等测试方法对Al-Er-Zr合金的时效析出过程及析出相Al3（Er1-xZrx）的粗化行为进行研究。结果表明：二元合金Al-0.04Er在375℃时效5 min后出现硬度峰（约为40.3HV）,随后迅速下降出现过时效;添加Zr能够显著提高其热稳定性,三元Al-Er-Zr合金中过时效现象显著滞后于Al-Er二元合金。在三元合金Al-Er-Zr中,随着Zr含量的增加,合金在长时间时效后,由于Er、Zr的协同析出而出现第二个更高的时效峰值,约为53.5HV,明显高于Al-Er二元合金的硬度。Al3（Er1-xZrx）粒子在高温粗化过程中逐渐长大,其平均直径d与退火时间t的关系符合LSW理论中的关系式。

英文摘要：

The aging behavior of dilute Al-Er-Zr alloy and the coarsening behavior of Al3（Erl-xZrx） precipitate were investigated by micro-hardness measurements, transmission electron microscopy and high resolution electron microscopy The results show that the maximum hardness of Al-0.04Er is 40.3HV, which is obtained after aging at 375 ℃ for 5 min, and the hardness decreases quickly with overaging. Overaging is delayed in Al-Er-Zr compared with the Zr-free alloy, which indicates that the addition of Zr improves the thermal stability of Al-Er alloy. In ternary alloy Al-Er-Zr, the hardness has a second peak as synergetic precipitation of Er and Zr; the second is 53.5HV, which is significantly higher than the peak hardness of Al-Er binary alloy. The Al3（Er1-xZrx） precipitate coarsens gradually at higher temperature. The average precipitation diameter （d） increases with aging time t as a function shown in LSW theory