On the role of CuAl₂precipitates in pitting corrosion of aluminum 2009/SiC_Wmetal matrix composite

The corrosion behaviors of an aluminum alloy 2009/SiCWcomposite material were studied by immersion and polarization tests in NaCl solution under as-rolled and peak-aged conditions. X ray diffraction analysis showed that the as-rolled composite consisted of three main phases. The presence of massive precipitation of CuAl2phase was considered as a result of no special control over the thermal condition of the forming process. The results of the immersion test showed that at increased immersion time, the composite surface became gradually covered with considerable amount of clusters of corrosion products.