Quantifying early-stage precipitation strengthening of Al–Mg–Zn(-Cu) alloy by using particle size distribution
Quantifying early-stage precipitation strengthening of Al–Mg–Zn(-Cu) alloy by using particle size distribution
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DOI：
10.1016/j.msea.2022.142851
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发表时间：
2022-02
期刊：
影响因子：
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通讯作者：
Y. Geng;Qi Song;Zhaorui Zhang;Yanlin Pan;Hongxiang Li;Yuan Wu;Huihui Zhu;Di Zhang;
中科院分区：
文献类型：
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作者：
Y. Geng;Qi Song;Zhaorui Zhang;Yanlin Pan;Hongxiang Li;Yuan Wu;Huihui Zhu;Di Zhang;
在过去的十年中，在5xxx系列Al-Mg合金的基础上，使用7 xxx系列合金中使用的Zn/Cu合金元素进行改性，产生了由T-Mg 32（AlZn（Cu））49相强化的新一代铝合金。由于T型析出相尺寸小，人工时效早期的析出强化行为一直是组织设计和工艺控制的障碍。本研究旨在通过透射电子显微镜和原子探针断层扫描的粒度分布来量化新开发的具有不同铜含量（0wt%和0.5wt%）的Al-Mg-Zn合金的早期沉淀强化行为，包括预时效和烘烤硬化。快速强化响应强烈依赖于Guinier-Preston区的数量密度和组成，在短期烘烤硬化处理过程中作为T相的前体的优先形核位置，并通过添加Cu显着增加。人工时效过程中不同类型相的共存可根据显微组织特征分为团簇、Guinier-Preston区和T′相。通过将三个单独分布的强度相加来量化合金的屈服强度，其中根据不同类型的析出物来评估析出强化。这些都是在合理的协议与报告的实验结果。这项研究揭示了预测合金的沉淀强化相结合的显微组织观察。
A new generation of aluminum alloys, strengthened by the T-Mg32(AlZn(Cu))49phase, has been created in the last decade based on the 5xxx series Al–Mg alloy, modified with Zn/Cu alloying elements used in 7xxx series alloys. The precipitation strengthening behavior in early stage artificial aging has been an obstacle to the microstructural design and processing control owing to the small size of T-precipitates. The present study aims to quantify the early stage precipitation strengthening behavior, including pre-aging and bake-hardening of the newly developed Al–Mg–Zn alloy with different Cu contents (0 wt% and 0.5 wt%), by particle size distribution via transmission electron microscopy and atom probe tomography. The rapid strengthening response strongly depends on the number density and constitution of Guinier-Preston zone acting as preferential nucleation sites for the precursor of T-phase during the short-term bake-hardening treatment and is significantly increased by the addition of Cu. The coexistence of different types of phases during artificial aging is categorized into clusters, Guinier-Preston zones, and T′ precipitates based on microstructural characterization. The yield strengths of the alloy were quantified by adding the strengths of three individual distributions, wherein the precipitation strengthening was evaluated according to the different types of precipitates. These are in reasonable agreement with the reported experimental results. This study sheds light on predicting the precipitation strengthening of alloys using a combination of microstructural observations.