In this study, the effects of pre-aging and natural aging on the clusters, strength and hemming performance of AA6014 Al–Mg–Si alloys with different Mg/Si ratios were investigated through three-dimensional atom probe (3DAP) in combination with tensile test and three-point bend test. Samples are subjected to natural aging (room temperature, ∼25 °C) or pre-aging (elevated temperature, 75 °C) treatments in order to generate different types of clusters. The number density, size and compositions of clusters are analyzed by 3DAP. The increased strength and deteriorated hemming performance are found in natural aged alloys, especially for Si-rich alloy. The hemmability is sensitive to the strength, and an increased strength leads to inferior hemmability. The formation of Mg₁Si₁ type cluster is encouraged during pre-aging treatment regardless of the alloy composition. Natural aging following directly water quenching promotes the formation of a large number density of small-sized Si-rich clusters in Si-rich alloy, whereas relatively low density of cluster with scattered Mg/Si ratios distribution in Mg-rich alloy. The concentration of the excess vacancies and the binding energy between vacancy and Mg and Si atoms plays an important role in the precipitation kinetics of cluster during different aging processes. Finally, the cluster and solid solution atoms statistics are utilized to predict the yield strength of the alloys in different aging conditions.

在这项研究中，通过三维原子探针（3DAP）结合拉伸研究了预时效和自然时效对不同Mg / Si比的AA6014 Al-Mg-Si合金的团簇，强度和包边性能的影响。测试和三点弯曲测试。样品经过自然老化（室温〜25°C）或预老化（高温75°C）处理，以生成不同类型的簇。通过3DAP分析簇的数量密度，大小和组成。在天然时效合金中，特别是对于富硅合金，发现强度增加且包边性能降低。可折弯性对强度敏感，而增加的强度导致可折弯性差。Mg ₁ Si ₁的形成不论合金成分如何，在预时效处理过程中均会鼓励型团簇。直接水淬后的自然时效促进了富硅合金中大量小尺寸富硅团簇的形成，而富镁合金中具有分散的Mg / Si比分布的团簇密度相对较低。在不同的时效过程中，过量空位的浓度以及空位与Mg和Si原子之间的结合能在簇的沉淀动力学中起着重要作用。最后，利用团簇和固溶体原子统计数据来预测不同时效条件下合金的屈服强度。