采用电导率测试、室温拉伸性能测试、扫描电镜和透射电镜分析等方法, 研究了不同的均匀化处理对铝锌镁钪合金组织和性能的影响。结果表明: 铸态铝锌镁钪合金为过饱和固溶体, 合金元素在晶界偏析, 形成了富锌、镁的非平衡共晶T相和富铁、硅、锰的杂质相; 当均匀化温度为350 ℃, 过饱和基体析出平衡相η-MgZn2; 随着均匀化温度的升高, 非平衡共晶T相逐渐溶入基体, 电导率下降, 晶内析出大量Al3(Sc, Zr)粒子, 合金的热加工性能提高; 470 ℃×12 h是试验合金较适宜的均匀化制度。

The effect of different homogenizing treatments on the microstructure and properties of an Al-Zn-Mg-Sc alloy was a studied by conductivity measuring, room temperature tensile property testing, scanning electron microscopy and transmission electron microscopy, et al. The results show that the as-cast Al-Zn-Mg-Sc alloy was a supersaturated solid solution, and the alloy elements segregated along grain boundaries to form the non-equilibrium eutectic T phase rich in Zn and Mg and the impurities rich in Fe, Si and Mn. When the homogenizing temperature was 350 ℃, the equilibrium phase η-MgZn2 precipitated from the supersaturated matrix. With the increase of homogenizing temperature, non-equilibrium eutectic T phase gradually dissolved into the matrix, the conductivity decreased and a lot of Al3(Sc, Zr) particles precipitated from the grains, and the thermal working property of the alloy increased. The fairly suitable homogenizing treatment precedure of the tested alloy was 470 ℃×12 h.