Abstract The effects of homogenization on dissolution and precipitation behaviors of intermetallic phase in a novel Zr and Er containing Al–Zn–Mg–Cu alloy were investigated. In this work, single-stage (SS:475 °C/24 h) and double-stage (DS:400 °C/12 h + 475 °C/24 h) homogenization treatments were carried out for the ingots with the heating rates of 300 °C/h, 50 °C/h and 25 °C/h, respectively. It was found that Er tended to segregate at the grain boundary in the form of Al8Cu4Er, and the formation mechanism was determined to be the eutectic reaction in the front of the solid/liquid interface during solidification. Also, Al8Cu4Er phase was detected to possess high melting point (~573.8 °C), which fully remained after the homogenization. Meanwhile, a significant impact of heating rate on the dissolution of intermetallic phases for the studied alloy under the DS homogenization was determined, but little impact was observed under the SS homogenization. Morever, the size and distribution of the dispersoids after homogenization were fully analyzed. It was found that slow heating rates was helpful to refine the particles size, and increase the density as well as volume fraction of the precipitation under both SS and DS homogenization. However a higher density and volume fraction of the precipitated particles, and a relatively larger average particle size were gained with DS homogenization.

中文翻译：

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均质化对含Zr和Er的Al-Zn-Mg-Cu合金金属间相溶解和析出行为的影响

摘要 研究了均质化对新型含 Zr 和 Er 的 Al-Zn-Mg-Cu 合金金属间相溶解和析出行为的影响。在这项工作中，对铸锭进行了单级（SS：475°C/24 h）和双级（DS：400°C/12 h + 475 °C/24 h）均质化处理，加热速率为分别为 300 °C/h、50 °C/h 和 25 °C/h。发现Er倾向于以Al8Cu4Er的形式在晶界偏析，形成机制确定为凝固过程中固/液界面前部的共晶反应。此外，检测到 Al8Cu4Er 相具有高熔点（~573.8 °C），在均质化后完全保留。同时，确定了加热速率对 DS 均质化下所研究合金金属间相溶解的显着影响，但在 SS 均质化下观察到的影响很小。此外，充分分析了均质化后分散体的大小和分布。结果表明，在 SS 和 DS 均化下，缓慢的加热速率有助于细化颗粒尺寸，并增加沉淀的密度和体积分数。然而，DS 均质化获得了更高的沉淀颗粒密度和体积分数，以及相对较大的平均粒径。结果表明，在 SS 和 DS 均化下，缓慢的加热速率有助于细化颗粒尺寸，并增加沉淀的密度和体积分数。然而，DS 均质化获得了更高的沉淀颗粒密度和体积分数，以及相对较大的平均粒径。结果表明，在 SS 和 DS 均化下，缓慢的加热速率有助于细化颗粒尺寸，并增加沉淀的密度和体积分数。然而，DS 均质化获得了更高的沉淀颗粒密度和体积分数，以及相对较大的平均粒径。