APPLICATION OF ELECTROCHEMICAL NOISE-ANALYSIS TO STUDY THE CORROSION BEHAVIOR OF ALUMINUM COMPOSITES

This paper investigates the possibility of using electrochemical voltage noise analysis to study the corrosion behavior of a few composite materials obtained by reinforcing an aluminum matrix with either SiC particles (SiCp) or Al2O3 particles (Al(2)O(3)p) or Al2O3 fibers (Saffil, Al(2)O(3)f). The ranking of the corrosion resistances exhibited by the various materials, according to the noise analysis technique, appears to agree with the results obtained by Linear polarization resistance and weight loss measurements and with the observation of the specimen surfaces by scanning electron microscopy. The recording of both polarization curves and galvanic current densities flowing between reinforced and nonreinforced aluminum electrodes shows that the driving force for the corrosion process is the cathodic process of oxygen reduction, which can be affected by the nature and the shape of the reinforcement.