(北京工業(yè)大學(xué) 材料科學(xué)與工程學(xué)院，北京 100124)
摘 要: 利用顯微硬度、TEM、HREM等測試方法對Al-Er-Zr合金的時效析出過程及析出相Al3(Er1-xZrx)的粗化行為進行研究。結(jié)果表明：二元合金Al-0.04Er在375 ℃時效5 min后出現(xiàn)硬度峰(約為40.3HV)，隨后迅速下降出現(xiàn)過時效；添加Zr能夠顯著提高其熱穩(wěn)定性，三元Al-Er-Zr合金中過時效現(xiàn)象顯著滯后于Al-Er二元合金。在三元合金Al-Er-Zr中，隨著Zr含量的增加，合金在長時間時效后，由于Er、Zr的協(xié)同析出而出現(xiàn)第二個更高的時效峰值，約為53.5HV，明顯高于Al-Er二元合金的硬度。Al3(Er1-xZrx)粒子在高溫粗化過程中逐漸長大，其平均直徑d與退火時間t的關(guān)系符合LSW理論中的關(guān)系式。
關(guān)鍵字: Al-Er-Zr合金；時效；析出強化；粗化
（School of Material Science and Engineering, Beijing University of Technology, Beijing 100124, China）
Abstract:The aging behavior of dilute Al-Er-Zr alloy and the coarsening behavior of Al3(Er1-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.
Key words: Al-Er-Zr alloys; aging; precipitation hardening; coarsening
