摘要
Aiming at understanding how intermetallic phases response when AA2024-T3 aluminium alloy is exposed to chloridecontainingaqueous medium, scanning electron microscopy was employed to provide morphological information on alloy surfacebefore and after corrosion testing. Energy dispersive X-ray spectroscopy was carried out to determine compositional change inintermetallic particles. Atomic force microscopy was used to examine topographical variation introduced by the reactions ofintermetallic phases. Transmission electron microscopy combined with ultramicrotomy was carried out on dealloyed Al2CuMgparticles and their periphery region. It is found that dealloyed Al2CuMg particles exhibited porous, polycrystalline structurecomprised of body-centred cubic copper particles with sizes of 5 to 20 nm. Aluminium matrix started to trench in the periphery ofAl2CuMg particles at the early stage of dealloying. Development of trenching in Al.Cu.Fe.Mn.（Si） particle’s periphery was notuniform and took longer time to initiate than Al2CuMg dealloying. Localized corrosion at a cluster of Al2CuMg and Al2Cu particleswas mainly associated with Al2CuMg particles.
为了深刻理解AA2024-T3 铝合金暴露在含氯水介质中金属间化合物相的响应方式,运用扫描电镜获得腐蚀试验前后合金表面的形貌信息,进行能谱分析确定金属间化合物粒子的成分变化,使用原子力显微镜检测金属间化合物相电化学反应所引起的高度变化,并对去合金金化的Al2CuMg 粒子及其周边区域进行透射电镜分析.研究发现,去合金化Al2CuMg 粒子为由5-20 nm 大小的体心立方铜粒子组成的多孔多晶体结构;在去合金化早期,铝基体就开始在Al2CuMg 粒子周边出现沟槽状腐蚀;Al-Cu-Fe-Mn.（Si）粒子周边沟槽状腐蚀的发展不均匀且比Al2CuMg 去合金化需要更长时间萌生;由Al2CuMg 和Al2Cu 组成的粒子簇的局部腐蚀主要与Al2CuMg 粒子相关.
基金
Project(51201157)supported by the National Natural Science Foundation of China
Project(H052013A003)supported by the National Defense Technology Foundation,China
Project supported by the UK-ESPRC LATEST2 Program
