Early-stage solute clustering and subsequent precipitation hardening phenomena in aluminum and magnesium alloys

可热处理铝合金由于具有多种理想的性能组合而成为最重要的工程材料之一。如果适当地开发这些合金的硬化能力，它们可以达到高强度水平。这种潜力对于汽车面板的应用是非常重要的，因为合金可以在油漆烘烤过程中硬化。这种工艺采用低成本的方法，加热时间短，温度低，在此过程中合金在纳米尺度上发生结构变化。深入了解这些变化和制造参数在决定这些变化方向方面的影响，可以为优化工艺和最大化成品强度提供必要的工具。最近，镁合金在轻量化结构部件的设计以及可降解生物材料方面也引起了人们的极大关注。目前生产的许多镁合金是可热处理的，并显示出硬化能力。然而，对加工对其硬化行为的影响还缺乏透彻的认识。

Heat treatable aluminum alloys have been widely used as one of the most important classes of engineering materials due to their combinations of desirable properties. These alloys can achieve high strength levels if their hardening capability is suitably exploited. This potential is of tremendous importance for automotive panel applications where the alloys can be hardened during paint baking processes. Such processes use cost-efficient routes with short heating times and low temperatures, during which the alloys undergo structural changes at nanometer scale. A deep understanding of these changes and the effect of manufacturing parameters in dictating the direction for these changes can provide the necessary tools for optimizing processes and maximizing the strength of the finished products. Recently, magnesium alloys have also attracted significant attention for the design of lightweight structural components, as well as degradable biomaterials. A number of currently-produced Mg alloys are heat treatable and have shown hardening capability. However, a thorough knowledge of the effect of processing on their hardening behaviour is lacking.