【摘要】 比较了添加和不添加0.3%（质量分数）Sc的AA7085合金的时效硬化响应、力学和耐腐蚀性能，并使用球差校正透射电子显微术和第一性原理计算揭示了Sc微合金化的微观机制。结果表明，AA7085-Sc合金强度的增加主要归因于Al晶粒尺寸的减小以及Al₃Sc@Al₃（Sc,Zr）核壳纳米颗粒和含Sc的η_p、GP-η_p纳米析出相数量密度的增加。在Al₃Sc@Al₃（Sc,Zr）/Al界面处存在强烈的应变场以及Zr与相邻基体Al原子之间明显的电子转移。Sc在GP-η_p和η_p中的掺杂抑制GP-η_p向η_p的转变。与7085合金相比，AA7085-Sc合金的耐腐蚀性得到改善，这与更细小的η相晶界沉淀物和更窄的晶界无析出带有关。基于多尺度的显微组织表征技术，揭示Sc微合金化后AA7085合金性能变化的原因。更多还原

【Abstract】 The age-hardening response, mechanical, and corrosion-resistant properties of AA7085 alloys with and without the addition of 0.3 wt.% scandium（Sc） were compared. Using advanced techniques such as aberration-corrected transmission electron microscopy and first-principles calculations, the underlying micromechanisms of Sc microalloying were revealed. Results show that the increase in strength of the AA7085-Sc alloy is mainly attributed to the decreased Al grain size and increased number density of both Al₃Sc@Al₃（Sc,Zr） core-shell nanoparticles and Sc-containing η_p and GP-η_p nanoprecipitates. Strong strain fields and evident electron transfer from Zr to the neighboring matrix Al atoms exist at the Al₃Sc@Al₃（Sc,Zr）/Al interface. The Sc doping in GP-η_p and η_p suppresses the GP-η_p → η_p transformation. Modified corrosion resistance of the AA7085-Sc alloy compared with AA7085 alloy is associated with the fine grain boundary precipitates of η phases and narrow precipitation free zone. The reasons of property changes of AA7085 alloy after Sc microalloying are explored based on the multiscale microstructural characterization.更多还原