Application of Quartz Crystal Microbalance to Corrosion Research
A quartz crystal microbalance (QCM) is capable of detecting small mass changes in the order of nano-grams from the changes in resonant frequency of a quartz oscillator. This article dealt with the principle of QCM and its application to corrosion research such as atmospheric corrosion and aqueous corrosion of metal thin films.
The corrosion kinetics and mechanisms of copper and iron thin films were discussed on the basis of typical results obtained by QCM combined with Auger electron spectroscopy and/or electrochemical technique. It was stressed that the heterogeneous corrosion, the stress generated in the film and the changes in the interfacial properties (viscosity and density) have to be taken into consideration as the factors influencing the resonant frequency which would provide the apparent mass changes. Moreover, the attempt to evaluate the vibration states of the quartz oscillator from the analysis of electrical equivalent circuit was introduced with respect to the deliquescence phenomena of salts adhered to the surface.