Application of electrochemical noise analysis to study the corrosion behaviour of aluminum composites

This paper investigates the possibility of using electrochemical voltage noise analysis to study the corrosion behaviorof a few composite materials obtained by reinforcing an aluminum matrix with either SiC particles (SiCp) or Al2O3 particles(Al2O3p) or Al2O3 fibers (Saffil, Al2O3f). 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 andweight loss measurements and with the observation of the specimen surfaces by scanning electron microscopy. The recordingof both polarization curves and galvanic current densities flowing between reinforced and nonreinforced aluminumelectrodes shows that the driving force for the corrosion process is the cathodic process of oxygen reduction, which can beaffected by the nature and the shape of the reinforcement.