Corrosion Mechanism of WCp/2024Al Metal Matrix Composite

The corrosion resistance of 11.4% WCp/2024Al metal matrix composite (MMC) and 2024Al in 3.5% NaCl solution was studied by means of potentiodynamic polarization. The results showed that the corrosion resistance of WCp/2024Al composite was poorer than that of the matrix. The addition of WC particles accelerated the corrosion rate of WCp/2024Al (MMC) greatly. By observing the corrosion test specimens after potentiostatic polarization, the corrosion mechanism of WCp/2024Al MMC was found to be synergy of galvanic corrosion between the WC and the matrix and galvanic corrosion between the phase rich in Cu and the phase poor in Cu. It was the reason that resulted in accelerating the corrosion rate.