Li Changlin, Li Xiwu, Zhang Yongan, Wen Kai, Yan Lizhen, Li Ying, Li Yanan, Yu Mingyang, Gao Guanjun, Yan Hongwei, Li Zhihui, Xiong Baiqing
State Key Laboratory of Nonferrous Structural Materials, China GRINM Group Co., Ltd., Beijing 100088, China.
GRIMAT Engineering Institute Co., Ltd., Beijing 101407, China.
Materials (Basel). 2025 May 13;18(10):2254. doi: 10.3390/ma18102254.
In this work, the effects of the Cu/Li ratio on the mechanical properties and corrosion behavior of Sc-containing Al-Cu-Li alloys were systematically investigated by utilizing age-hardening behavior, tensile property, corrosion behavior, and electrochemical behavior, complemented by microstructural characterization through EBSD and TEM. The results show that the peak aging strength of the alloys remained relatively consistent but slightly decreased with the decrease in Cu/Li ratio, and the yield strengths were 585 MPa, 578 MPa, and 573 MPa, respectively. The changes in the Cu/Li ratio caused different matching patterns of precipitates in the peak aging alloys. The cumulative precipitation strengthening by T, θ', δ', and S' phases are equal within the alloys with different Cu/Li ratios. However, the strength contribution of the T phase decreases from 81% to 66% with the decrease in the Cu/Li ratio. Concurrently, the precipitates of LAGBs gradually increase in number and are continuously distributed, and the precipitates of HAGBs become larger in size with lower Cu content as the Cu/Li ratio decreases, all of which leads to a weakening of the intergranular corrosion (IGC) resistance within the low Cu/Li ratio alloy.
在本工作中，通过时效硬化行为、拉伸性能、腐蚀行为和电化学行为，并辅以电子背散射衍射（EBSD）和透射电子显微镜（TEM）的微观结构表征，系统研究了铜锂比对含钪铝铜锂合金力学性能和腐蚀行为的影响。结果表明，合金的峰值时效强度保持相对一致，但随着铜锂比的降低略有下降，屈服强度分别为585MPa、578MPa和573MPa。铜锂比的变化导致峰值时效合金中析出相的匹配模式不同。在不同铜锂比的合金中，T、θ'、δ'和S'相的累积析出强化作用相当。然而，随着铜锂比的降低，T相的强度贡献从81%降至66%。同时，随着铜锂比降低，低角度晶界（LAGBs）析出相数量逐渐增加且连续分布，高角度晶界（HAGBs）析出相尺寸随着铜含量降低而变大，所有这些导致低铜锂比合金的抗晶间腐蚀（IGC）能力减弱。
