Zn添加对预时效处理的Al-Mg-Si-Cu合金原子团簇行为和烤漆硬化响应的影响

Effect of Zn addition on clustering behavior in a pre-aged Al-Mg-Si-Cu alloy and its relation to bake hardening response

摘要:

本文通过显微硬度、透射电镜和三维原子探针表征测试手段，研究了Zn添加对Al-Mg-Si-Cu合金原子团簇行为和烤漆硬化响应的影响。结果表明，经100°C/3h预时效处理后，含Zn和不含Zn合金中均形成了Mg-Si原子团簇。然而，与不含Zn的合金相比，含Zn合金中Mg-Si原子团簇数量更多，表明Zn添加促进了Mg-Si原子团簇的形成。经185°C /25min烤漆处理后，两个合金在预时效过程中形成的Mg-Si原子团簇转变为具有明显增强效果的β″相，对应的烤漆增量也明显增加。由于预时效后的含Zn合金中Mg-Si原子团簇数量更多，这为烤漆过程中β″的形成提供了更多的形核核心。因此，含Zn合金β″相的尺寸更小，分布更致密，相对应的烤漆硬化响应速率也得以增强。

关键词:Al-Mg-Si-Cu 合金;Zn 添加;原子团簇行为;烤漆硬化响应

Abstract:

The effect of Zn addition on clustering behavior in a pre-aged Al-Mg-Si-Cu alloy and its relation to bake hardening response are investigated. After pre-aging at 100 °C for 3 h, the Zn addition prompts the formation of clusters with a uniform Mg/Si ratio, which can easily transform into β" phases. Consequently, a fine and dense distribution of β" phases is observed in the Al-Mg-Si-Cu alloy with Zn addition during bake hardening treatment at 185 °C for 25 min after pre-aging. This correlates well with the enhanced bake hardening response of the Al-Mg-Si-Cu alloy with Zn addition.

Key words:Al-Mg-Si-Cu alloy, Zn addition, clustering behavior, bake hardening response