7Cu2Fe，Al8Cu4Ho 及S (Al2CuMg)，第二相導(dǎo)致合金元素分布存在嚴(yán)重微觀偏析。合金在475 ℃均勻化熱處理20 h后，T相完全回溶基體且未觀察到S相，僅剩余Al7Cu2Fe和Al8Cu4Ho。硬度和電導(dǎo)率隨T相的回溶而變化，T相的回溶使得合金硬度升高，電導(dǎo)率降低。同時(shí)，在475 ℃均勻化熱處理5~20 h過程中，Al3Ho相析出，這一現(xiàn)象引起硬度和電導(dǎo)率的升高。結(jié)合均勻化動(dòng)力學(xué)分析，確定合金適宜的均勻化熱處理制度為470~475 ℃/20~25 h。;Homogenization treatment for Al-Zn-Mg-Cu alloy with Ho addition was investigated by scanning electron microscope (SEM), optical microscope (OM), and differential scanning calorimeter (DSC). Electrical conductivity and micro-hardness were tested during different homogenization processes. The results show that there are four kinds of second phases in as-cast alloy: T(AlZnMgCu), Al7Cu2Fe, Al8Cu4Ho and S (Al2CuMg), which cause severe micro-segregation in microstructure. After homogenization treatment at 475 °C for 20 h, T phase is completely dissolved back into matrix and no S phase is observed, with Al7Cu2Fe and Al8Cu4Ho remaining. Micro-hardness and electrical conductivity are associated with vibration of T phase, dissolution of which can increase micro-hardness and decrease electrical conductivity. Besides, precipitation of Al3Ho also contributes to the increase in both micro-hardness and electrical conductivity during homogenization at 475 °C for 5~20 h. Finally, through homogenization kinetic analysis, the appropriate homogenization parameter is determined as 470~475 °C/20~25 h."/>