Metastable phases in aluminium alloys are the primary nano-scale precipitates which have the biggest contribution to the increase in the tangible mechanical properties. The continuous increase in hardness in the 7xxx aluminium alloys is associated with the phase transformation from clusters or GP-zones to the metastable η′ phase. The high-resolution electron imaging is used to observe the precipitates and reconstruct a kinetic model that might explain the transformation. This work is an attempt to gain insight into how the structural transformation may occur based on the shortest route of diffusion for the eventual structure to result in that of the η′ phase.

中文翻译：

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7xxx 铝中亚稳相的可能转变机制

铝合金中的亚稳相是主要的纳米级析出物，对有形力学性能的提高贡献最大。7xxx 铝合金硬度的持续增加与从簇或 GP 区到亚稳态 η' 相的相变有关。高分辨率电子成像用于观察沉淀物并重建可能解释转变的动力学模型。这项工作试图基于最终结构的最短扩散路径来深入了解结构转变如何发生，从而导致 η' 相。