Application of Multipoint Impedence Spectroscopy to Corrosion Monitoring on Shape Memory Alloys in Smart Building Materials.

Abstract

Impedance spectroscopy has been widely employed in order to monitor the hydration phenomena which reflect the electrical conduction along the porous paths whose ionic features are easily discerned from the electrode polarization. The microstructural changes influence the impedance features composed of resistors, capacitors, and inductors, through their intermixed connections involving series, parallel or, both. Unlike the application of impedance spectroscopy to the bulk phenomena, the three-point impedance spectroscopy can be exploited towards the rational separation of a specific electrode from the remaining system through the multipoint electrode configuration in order to localize the corrosion responses of the electrode under interest. The effects of the electrode configuration are investigated in order to establish the methodology on the corrosion monitoring in reinforcement materials in building materials. The current work chooses Ni/Ti-Based and Fe-Based shape memory alloys as model systems in monitoring the corrosion phenomena encountered in construction applications. The shape memory alloys are mixed with the cement-based materials with the aim to providing self-healing functions in association with the detrimental cracks in smart composite materials. In particular, the Ni-Ti and Fe-Si shape memory alloys are subjected to corrosion environments in everyday and hostile conditions. The conventional potentiostat approaches are performed in parallel, in order to prove the applicability of the multipoint impedance spectroscopy in the electrochemical applications involving nano-materials. The ramifications of multi-point impedance spectroscopy are discussed towards corrosion-specific monitoring in functional shape memory alloys which is recommended as one of powerful next-generation building materials.