【作者】 韩超； 于美； 李松梅； 刘建华；

【Author】 Han Chao;Yu Mei;Li Song-mei;Liu Jian-hua;Beijing University of Aeronautics and Astronautics;

【机构】 北京航空航天大学材料科学与工程学院；

【摘要】 铝锂合金具有低密度、高弹性模量、高的比强度及比刚度,展现出良好的综合性能。在第三代2297铝锂合金中,Cu元素含量的提升使T₁相（Al₂CuLi）数量增加,提高合金强度,但会导致其它富Cu相Al₇Cu₂Fe的数量增加。同时在合金中通过添加Mn元素可以形成Al₆Mn金属间化合物,Al₆Mn可以细化晶粒,起到降低合金各向异性的作用。在关于2297铝锂合金腐蚀行为的研究中表明,形状不规则的粗大析出相AlCuMnFe是造成合金发生腐蚀的主要原因,AlCuMnFe相主要由Al₇Cu₂Fe和Al₆Mn两种金属间化合物组成,成分不均一,增加了点蚀研究的复杂性。本文概述了铝锂合金中Al₇Cu₂Fe、Al₆Mn等不同金属间化合物在NaCl溶液引起的点蚀中所起的作用,并基于第一性原理探讨了AlCuMnFe析出相的内部特点以及AlCuMnFe相整体在腐蚀过程中的作用,对NaCl溶液中铝锂合金的点蚀形成进行阐述。更多还原

【Abstract】 Aluminum-lithium alloy has low density,high elastic modulus,high specific strength and specific stiffness,showing good comprehensive performance.In the third-generation 2297 Al-Li alloy,the rise of Cu element content increases the number of T₁ phase（Al₂CuLi） and improves strength of alloy,but leads to the increase of other Cu-rich phase,such as Al₇Cu₂Fe.The study on the corrosion behavior of 2297 Al-Li alloy shows that the irregular coarse phase AlCuMnFe is the main reason for the corrosion of the alloy.AlCuMnFe phase is mainly composed of Al₇Cu₂Fe and Al₆Mn,with heterogeneous compositions,which increases the complexity of the study on pitting.In this paper,the role of Al₇Cu₂Fe,Al₆Mn in Al-Li alloy about pitting corrosion in NaCl solution was summarized.Based on the first principle,the internal characteristics of AlCuMnFe and the overall role of AlCuMnFe phase in the corrosion process were discussed,and the pitting formation of Al-Li alloy in NaCl solution was also described.更多还原