Characterization of aluminum corrosion with a quartz crystal analyzer

A quartz crystal analyzer is utilized to monitor the corrosion process of an aluminum surface. A quartz crystal having 2000 Angstrom of aluminum layer is installed in a specially designed cell and is in contact with an electrolyte solution. While a constant potential is applied to the cell, the resonance frequency and resonance resistance are simultaneously measured using the analyzer. In addition, surface topographs are taken with an atomic force microscope and the element analysis of the surface is conducted using an energy dispersive X-ray spectrometer. We believe that the resonance frequency and the resonance resistance during the corrosion process can be explained by the change of surface structure caused by the corrosion. The amount of surface metal dissolution affects the variation of the resonance frequency and the resonance resistance due to the mass changes of surface metal and entrapped liquid and surface roughness. These are supported by the surface topograph and element analysis, and it is found that a simple measurement using the quartz crystal analyzer can replace the complex monitoring employing large equipments in the investigation of a corrosion process of metal surface. (C) 1999 Elsevier Science B.V. All rights reserved.