This paper discusses the influence of Vietnam rare earth (RE) with the composition of 69.4% Ce and 30.5% La (modification content of 4% and 6%) on the microstructure and mechanical properties of Al–5Zn–3.5Mg–1.2Cu alloy when the temperature modification is changed at [Formula: see text] in 150, 200, 250 s. By optical microscopy, the results showed that the microstructure of the modified sample is finer than the nonmodified sample. By the SEM and EDS analysis, at the grain boundaries of this alloy, [Formula: see text] and/or [Formula: see text] intermetallic phases appeared. The modified elements (La, Ce) in RE and aluminum were formed in the intermetallic [Formula: see text] and [Formula: see text] phases, which prevents the development of the dendritic [Formula: see text] phase. The result showed Al–5Zn–3.5Mg–1.2Cu alloy modified with 4% RE in 150 s which is the most optimal result, the grain size is [Formula: see text] and the hardness is 107 HB.

中文翻译：

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稀土对Al-Zn合金显微组织和力学性能的影响

本文讨论了成分为 69.4% Ce 和 30.5% La（变质含量分别为 4% 和 6%）的越南稀土 (RE) 对 Al-5Zn-3.5Mg-1.2Cu 合金显微组织和力学性能的影响当在 150、200、250 秒内在 [公式：见文本] 处改变温度修正时。通过光学显微镜，结果表明改性样品的微观结构比未改性样品更精细。通过SEM和EDS分析，在该合金的晶界处出现了[分子式：见正文]和/或[分子式：见正文]金属间相。RE和铝中的改性元素（La，Ce）在金属间[化学式：见正文]和[化学式：见正文]相中形成，阻止了树枝状[化学式：见正文]相的发展。结果显示Al-5Zn-3.5Mg-1。