EFFECT OF HEAT TREATMENT ON PITTING CORROSION RESISTANCE OF 6061 Al/SiC_p COATED BY THE CERIUM OXIDE FILM IN 3.5 N NaCl SOLUTION

摘要

One of the main drawbacks of 6061 Al/SiC_p is its poor pitting corrosion resistance in the aggressive environment containing chloride ions, such as seawater, for example. The present article deals with the investigations of effects of aging on the corrosion behavior of 6061 Al/SiC_p and of the heat treatment on the pitting corrosion resistance of 6061 Al/SiC_p coated by cerium oxide prepared by chemical bath technique. Potentiodynamic polarization test was used to study the corrosion behavior of cerium oxide coatings in 3.5N NaCl solution. The microstructure of cerium oxide was examined by scanning electron microscopy (SEM) and the formed phases were identified by X-ray diffraction (XRD). The pitting corrosion resistance of the cerium oxide coating was found to be improved after heat treatment at 300℃ for 30 min.