Abstract The effect of Mg content on the precipitation behavior and resultant mechanical properties of high Zn-content Al–Zn alloy was studied by adding Mg to Al–20Zn alloy. The dynamic precipitation of Zn and η phases occurred in the Al–Zn–Mg alloys during hot rolling. The Zn phase promoted the precipitation of the η phase, which increased in size with increasing Mg content. Mg addition led to the decomposition of Al–Zn supersaturated solid solution and the precipitation of the η′ phase during natural aging at room temperature. In addition to the η′ phase, the nano-sized Zn phase precipitated in high Zn-content Al–Zn–Mg alloy during artificial aging at 120 °C. The analysis of mechanical properties showed that 0.5 wt% Mg addition can enhance the strength of Al–20Zn alloy after rolling and heat treatments due to the presence of nano-sized η and η′ precipitates. However, when Mg content was increased to 1 wt%, the mechanical properties of the rolled and heat-treated Al–20Zn alloy deteriorated due to the complete decomposition of Al–Zn solid solution and extremely large amount of solute atoms.

中文翻译：

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高Zn浓度Al-Zn-Mg合金的析出行为及力学性能

摘要 通过在Al-20Zn合金中添加Mg，研究了Mg含量对高Zn含量Al-Zn合金析出行为和力学性能的影响。在热轧过程中，Al-Zn-Mg 合金中发生了 Zn 和 η 相的动态析出。Zn 相促进了 η 相的析出，随着 Mg 含量的增加，η 相的尺寸增加。添加Mg导致Al-Zn过饱和固溶体的分解和室温下自然时效过程中η'相的沉淀。除了 η' 相外，在 120 °C 人工时效过程中，高 Zn 含量的 Al-Zn-Mg 合金中还会析出纳米尺寸的 Zn 相。力学性能分析表明，0. 由于纳米尺寸的 η 和 η' 析出物的存在，5 wt% Mg 添加量可以提高 Al-20Zn 合金在轧制和热处理后的强度。然而，当 Mg 含量增加到 1 wt% 时，由于 Al-Zn 固溶体完全分解和大量溶质原子，轧制和热处理的 Al-20Zn 合金的力学性能恶化。