Pitting corrosion of A357 aluminium alloy obtained by semisolid processing

This paper studies the pitting corrosion of a structural component of A357 aluminium alloy obtained by a semisolid metal forming process. The mechanical properties of the A357 alloy were improved by applying standard heat treatments T5 and T6. Impedance measurements were conducted at the rest potential and polarisation curves were plotted using a 3% NaCl test solution. After polarisation experiments the specimens were analysed by scanning electron microscopy. The corrosion process is favoured through the eutectic regions. The results show that T6 heat treatment improved the corrosion resistance of the A357 aluminium alloy.