Influence of Thermomechanical Processing on the Corrosion Behaviour of Aluminium (6063)-SiCp Composites in NaCl and H2SO4 Environment

The influence of thermomechanical treatment on the corrosion behaviour of silicon carbide particulate reinforced aluminium (6063) composites in 3.5 wt% NaCl and 0.3M H2SO4 solution was investigated. Aluminium (6063) – SiC particulate composites having 6 and 9 volume fraction of SiC were produced using two-step stir casting process. The composites were cold rolled to 20 % and 35 % deformation before solution heat-treating at 550oC for 1hour followed by rapid cooling in water. Mass loss and corrosion rate measurements were utilized as criteria for evaluating the corrosion behaviour of the composites. It was observed that aluminium (6063) – SiCp composites exhibited superior corrosion resistance in 3.5 wt% NaCl solution when compared to 0.3M H2SO4 solution. Furthermore, the thermomechanical treatment resulted in significant improvement in the corrosion resistance of the composites in H2SO4 solution.