Establishing SCC test facility with micro electrochemical attachment and in situ high resolution visualizaton system

In metallic materials, corrosion and stress corrosion is a sensitive function of microstructure, in particular the local electrochemical activities of several microstructural heterogeneities such as second phase particles and grain boundaries. The microstructural heterogeneities could act as a local corrosion site, which under stressed condition often develops into a stress corrosion crack. On the other hand in engineering components, structural heterogeneities of a higher scale could be produced by joining and processing techniques such as welding (eg. heat affected zone and nugget), cutting and machining operations; all have tremendous influence on corrosion and stress corrosion.

In all the above cases, in-situ visualization of local corrosion / stress corrosion process in solution using a high resolution video microscope system with a wide range of magnifying capability could provide significant information on how the various microstructural factors controlling the corrosion performance of engineering materials. A typical example is the in-situ visualization of initiation of stress corrosion cracks adjacent to intermetallic particles in aluminium alloys assisted by the local corrosion processes.

This project aims to develop a SCC test facility attached with micro electrochemical set up for fine scale electrochemical measurements and a high resolution visualization system for viewing the corrosion/SCC in-situ.