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

This paper investigates the possibility of using electrochemical volta ge noise analysis to study the corrosion behavior of a few composite m aterials obtained by reinforcing an aluminum matrix with either SiC pa rticles (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 t he various materials, according to the noise analysis technique, appea rs to agree with the results obtained by Linear polarization resistanc e and weight loss measurements and with the observation of the specime n surfaces by scanning electron microscopy. The recording of both pola rization curves and galvanic current densities flowing between reinfor ced 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 reinforceme nt.