Abstract To provide insight to the relationships between quenching rate and aging treatment on the microstructure and properties of Al–Zn–Mg alloys, 7046 A alloy, a low Cu-content commercial Al–Zn–Mg alloy, was selected in the present study. As-received hot-extruded 7046 A alloys were quenched in air and room temperature water and then aged at 120 °C for 0–120 h. The mechanical behavior, corrosion resistance and microstructures of the aged alloy were compared and analyzed. The experiment result shows that quenching rate exhibits a greater influence on the precipitates and precipitation free zones (PFZs) of aged alloys than over-aging treatment and the reasons have been discussed. The η equilibrium phases preferentially take the Al3Zr and Al6Mn dispersoids as the heterogeneous nucleation core and grow quickly inside the grains during the slow cooling process. Over-aging treatment would broaden the grain boundary PFZ and the space of grain boundary precipitates, thus improving the corrosion resistance of water quenched alloys, while it is harmful to air quenched (AQ) alloys. Pitting resistance can be summarized as: AQ24

中文翻译：

---

淬火速率和过时效对Al-Zn-Mg (7046A)合金显微组织、力学性能和耐腐蚀性能的影响

摘要 为了深入了解淬火速率和时效处理对 Al-Zn-Mg 合金显微组织和性能的关系，本研究选择了 7046 A 合金，一种低 Cu 含量的商用 Al-Zn-Mg 合金。收到的热挤压 7046 A 合金在空气和室温水中淬火，然后在 120°C 下时效 0-120 小时。对时效合金的力学行为、耐蚀性和显微组织进行了比较和分析。实验结果表明，与过时效处理相比，淬火速率对时效合金的析出物和无析出区（PFZs）的影响更大，并讨论了原因。η 平衡相优先采用 Al3Zr 和 Al6Mn 弥散体作为异质成核核，并在缓冷过程中在晶粒内部快速生长。过时效处理会加宽晶界PFZ和晶界析出物的空间，从而提高水淬合金的耐腐蚀性能，但对空淬(AQ)合金有害。耐点蚀性可概括为：AQ24