Mechanical Property and Corrosion Behavior of SiCp/2A50 Composites Prepared by Liquid Forging

The mechanical properties and the corrosion mechanism of SiCp/2A50 composite materials were studied. The specimens were prepared by the liquid forging. The SiCp particles were added into a partially solidified matrix alloy. The experimental results show that the strength of SiCp/2A50 composite increases with increasing of the SiCp volume fraction, and the ductility of SiCp/2A50 composite decreases with increasing particulates size. The pitting potentials of 2A50 and SiCp/2A50 composite materials are similar. The corrosion resistance of SiCp/2A50 of the pit initiation is almost the same as that of the matrix alloy. It has been found that once pits initiate, the pitting corrosion damage is accelerated owing to the formation of crevices between the reinforcement and the matrix. The cathodic current of the SiCp/2A50 is slightly larger than that of the matrix alloy. The SiCp markedly decreases the pitting corrosion resistance of the composite and the matrix alloy in chloride containing environment. SiCp accelerates the corrosion rate of composite materials, namely the corrosion velocity of composite materials is greater than that of the aluminum alloys.