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。
Aiming at understanding how intermetallic phases response when AA2024-T3 aluminium alloy is exposed to chloride-containing aqueous medium, scanning electron microscopy was employed to provide morphological information on alloy surface before and after corrosion testing. Energy dispersive X-ray spectroscopy was carried out to determine compositional change in intermetallic particles. Atomic force microscopy was used to examine topographical variation introduced by the reactions of intermetallic phases. Transmission electron microscopy combined with ultramicrotomy was carried out on dealloyed Al2CuMg particles and their periphery region. It is found that dealloyed Al2CuMg particles exhibited porous, polycrystalline structure comprised of body-centred cubic copper particles with sizes of 5 to 20 nm. Aluminium matrix started to trench in the periphery of Al2CuMg particles at the early stage of dealloying. Development of trenching in Al?Cu?Fe?Mn?(Si) particle’s periphery was not uniform and took longer time to initiate than Al2CuMg dealloying. Localized corrosion at a cluster of Al2CuMg and Al2Cu particles was mainly associated with Al2CuMg particles.
参考文献
- 下载量()
- 访问量()
- 您的评分：
-
10%
-
20%
-
30%
-
40%
-
50%