CORROSION STUDY OF AL2O3 DISPERSION-STRENGTHENED CU METAL-MATRIX COMPOSITES IN NACL SOLUTIONS

The corrosion behaviour of alumina dispersion strengthened (DS) copper in 3.5% NaCl solution was studied and compared to the behaviour of pure copper using electrochemical techniques, scanning electron microscopy (SEM), X-ray diffraction, and inductively coupled argon plasma atomic emission spectroscopy (ICP-AES). The corrosion surface products were identified as predominantly copper chloride. It was found that DS copper has similar corrosion characteristics to pure Cu under aerated, open to air and deaerated conditions. The effects of alumina particles and the presence of oxygen in the solutions on the behaviour of the DS Cu were examined. The corrosion mechanism involved is discussed in terms of the roles of the surface CuCl film formation and dissolution during the corrosion process.