Fig xA Cross section backscattered electron image

3.2.4. Microstructural analysis of corroded windows profile
3.2.4.1. Surface morphology
Surface morphology of a localised corroded region from the corroded AA6060 window profile is shown in Fig. 9. The overall size of the corroded area was approximately 1.6 mm, which consists of a number of pits and cracks at the surface. The EDS analysis (not shown here) of the corroded pits showed the presence of chloride ions.
Fig. 9. AA6060 secondary PHA-767491 image of localised corrosion attack on window profile.Figure optionsDownload full-size imageDownload as PowerPoint slide
3.2.4.2. Metallographic cross-section analysis
The metallographic cross section of a localised corrosion attack is shown in Fig. 10. Cross section of the corroded pit shows pelagic zone the penetration depth of the corrosion attack is not uniform. Moreover intergranular corrosion attack was observed at the bottom of the pit. Intergranular corrosion is penetrated vertically down ward up to a depth of approximately 250 μm.