The tensile properties and corrosion behaviours of an ageing Al-1.7 Cu-4.0 Li- 0.4 Mg alloys (in at. %) with or without 0.3 Zn addition were investigated by detailed microstructure evolution using TEM and STEM. Herein, the Zn addition to the Al-1.7 Cu-4.0 Li- 0.4 Mg ageing alloy is determined as a convincing approach to optimising the strength-corrosion resistance balance. With Zn addition, the increasing quantity of T₁ phase in grain led to the increase of the tensile property of the Al-1.7 Cu-4.0 Li- 0.4 Mg alloy. While the studied alloy with Zn addition possessed preferable corrosion resistance in respect of intergranular corrosion (IGC) depth reducing. Moreover, the emergence of Zn elements in the coarse phases at grain boundary (GB) may decrease the potential differences between the precipitates at GB and free precipitation zone (PFZ), which could increase corrosion resistance.

通过使用TEM和STEM进行详细的微观组织演变，研究了添加或不添加0.3 Zn的时效Al-1.7 Cu-4.0 Li- 0.4 Mg合金（以原子百分比计）的拉伸性能和腐蚀行为。在本文中，确定在Al-1.7 Cu-4.0 Li- 0.4 Mg时效合金中添加Zn作为优化强度-耐蚀性平衡的有效方法。随着锌的添加，T _1的数量增加晶粒中的相导致增加了Al-1.7 Cu-4.0 Li- 0.4 Mg合金的拉伸性能。研究的添加锌的合金在减少晶间腐蚀（IGC）深度方面具有较好的耐腐蚀性。此外，在晶界（GB）处的粗相中锌元素的出现可以减小GB处的析出物与自由析出区（PFZ）之间的电势差，从而可以提高耐蚀性。