( 东北大学 材料与冶金学院, 沈阳 110004)
摘 要: 熔制了Al-Zn-Cu系的13个不同成分的合金， 并进行了组织均匀化和平衡冷却至200℃的缓冷处理。 通过显微组织观察、 X射线衍射分析和电子探针微区成分分析， 测定了这13个合金的相组成及成分。 结果表明， 在200℃时， 富铝角/α/相的Zn、 Cu、 Al含量（摩尔分数）分别为6.7%、 2.0%和91.3%， 确定了/T/′相的成分范围以及Al2Cu3相中Zn的溶解度（摩尔分数）小于4.4%， 绘制出了Al-Zn-Cu系200℃低Cu侧的等温截面相图。
关键字: 相图； Al-Zn-Cu三元系； T′相； α相
（ School of Materials and Metallurgy,
Northeastern University, Shenyang 110004, China）
Abstract: The phase composition and constituent of 13 designed alloys in Al-Zn-Cu system were analyzed by optical microscope, X-ray diffraction and EPMA method. These samples were prepared through sufficient homogenization and equilibrium cooling heat treatment from 400℃ to 200℃. The results show that the contents(in mole fraction) of Zn, Cu and Al of α phase ( rich aluminum phase) at 200℃ are 6.7%， 2.0% and 91.3% respectively. The composition range of T′ phase was determined and the solubility(in mole fraction) of Zn in Al2Cu3 is less than 4.4%. The isothermal section diagram of Al-Zn-Cu system on lower copper side at 200℃ was constructed.
Key words: phase diagram; Al-Zn-Cu system; T′ phase; α phase
