Effect of composite on the early- and mid-stage precipitation hardening phenomena in Al-Mg-Si (Cu)

Al-Mg-Si-(Cu)合金，即AA6xxx，通常被用作汽车、大众运输和结构应用的中等强度合金。特别是，由于其比强度、耐腐蚀性、表面外观和可回收性，它们是汽车蒙皮面板的轻质合金选择。合金通过时效硬化处理获得所需的强度，在此过程中会发生一系列复杂的溶质原子聚集和纳米级硬化颗粒析出的相变过程。以前的研究已经提供了关于合金成分和/或热处理路线对硬化沉淀物的类型或析出过程的变化的影响的重要信息。然而，成分对相变影响的潜在机制仍然不明确或未经证实。拟议工作的目标是使用最先进的原子和纳米级表征技术以及宏观测试方法，以更好地了解成分和时效历史对Al-Mg-Si-(Cu)合金中具有重要商业意义的沉淀硬化行为的作用。

Al-Mg-Si-(Cu), i.e. AA6xxx, alloys are commonly used as medium strength alloys for automotive, mass transportation, and structural applications. In particular, they are the light alloy of choice for automotive skin panels owing to their specific strength, corrosion resistance, surface appearance, and recyclability. The alloys acquire their desired strength through age hardening treatments, during which phase transformation processes involving a complex sequence of solute atom clustering and precipitation of nano-scale hardening particles take place. Previous studies have provided important information on the effect of alloy composition and/or heat treatment routes on the type of hardening precipitates or changes in precipitation processes. However, the underlying mechanisms for the effect of composition on phase transformations remain ambiguous or unverified. The goal of the proposed work is to use the state-of-the art atomic- and nano-scale characterization techniques, as well as macro-scale testing methods, to acquire a better understanding of the role of composition and aging history on the commercially-important precipitation hardening behaviour in Al-Mg-Si-(Cu) alloys.