中文摘要：

采用光学显微镜（OM）、差热分析（DTA）、扫描电镜（SEM）、透射电镜（TEM）和X射线衍射（XRD）等分析技术研究了在Al-Zn-Mg-Cu-Zr合金中添加微量稀土元素Er和Y对其均匀化行为的影响。研究结果表明：在Al-Zn-Mg-Cu-Zr合金中复合添加微量Er,Y（质量分数〈0.4%）使合金的共晶化合物溶解温度升高,其均匀化温度相应提高。合金经二级均匀化处理后仍残留较多的S（Al2CuMg）相和Al8Cu4Er相,其中S（Al2CuMg）相能在三级均匀化条件下得到有效消除,但Al8Cu4Er相很难消除。经465℃/24h＋475℃/4h＋485℃/4h三级均匀化处理后,合金中残留的共晶化合物数量已经很少,基体上分布有大量、均匀、细小的第二相质点,对抑制合金再结晶,提高合金性能十分有利。

英文摘要：

Effect of minor Er and Y addition to Al-Zn-Mg-Cu-Zr alloy on the homogenizing behavior were studied by means of optical microscope（OM）,different temperature analysis（DTA）,scanning electron microscope（SEM）,transmission electron microscope（TEM） and X-ray diffraction（XRD）.The results indicate that when microalloying with minor Er and Y addition（gross 0.4%） to Al-Zn-Mg-Cu-Zr alloy,the dissolution temperature of the pseudo eutectic of the alloy rises,and the homogenizing temperature rises accordingly.After two-step homogenizing process,there is a few of the rudimental eutectic compounds for Al2CuMg and Al8Cu4Er phase in the alloy.The Al2CuMg phase dissolves after three-step homogenizing process,but the dissolution of the Al8Cu4Er phase is more difficult.After the three-step homogenizing process（annealing 465℃ /24h ＋ 475℃ /4h ＋ 485℃ /4h）,the rudimental eutectic compound is little,and a large number of the fine particles of the second phase are uniformly precipitated in the matrix,which is advantageous to restraining recrystallization of the alloy and raising the mechanical properties of the alloy.