ABSTRACT The effect of erbium and homogenization on microstructures and mechanical properties of AA7075 alloy were investigated using optical microscope (LIMI), scanning electronic microscope (SEM) equipped with energy dispersive X-ray detection (EDS) and mechanical testing. It was found that during solidification most of the elements Er and Cu segregated at the grain boundaries in the form of Al3ErCu or Al8Cu4Er and a very small part of Er dissolved in the FCC-Al matrix. The latter is not completely reclaimable for heterogeneous nucleation and refine grain FCC-Al matrix in its as-cast state. Er and Cu- containing phases fragmented into fine particles after extrusion and these led to a slight increase in grain boundary strengthening. The process of homogenizing, extruding and aging the Er containing alloys considerably improved the strength due to precipitation. The analysis of the extruded sample showed that the addition of Er can slightly retard the recrystallizing behavior of AA7075 alloy.

中文翻译：

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Er改性AA7075合金的组织和力学性能

摘要 采用光学显微镜 (LIMI)、配备能量色散 X 射线检测 (EDS) 的扫描电子显微镜 (SEM) 和力学测试研究了铒和均质化对 AA7075 合金组织和力学性能的影响。发现在凝固过程中，大部分元素 Er 和 Cu 以 Al3ErCu 或 Al8Cu4Er 的形式在晶界偏析，而极少部分 Er 溶解在 FCC-Al 基体中。后者不能完全回收用于异质成核和细化晶粒 FCC-Al 基体在其铸态。挤压后含 Er 和 Cu 相破碎成细颗粒，这导致晶界强化略有增加。均质化过程，挤压和时效含铒合金由于析出而显着提高了强度。对挤压样品的分析表明，Er 的加入可以略微延迟 AA7075 合金的再结晶行为。