Studies on the corrosion resistance of Al7075 / SiC metal matrix composites in an alkaline environment

Abstract

Metal matrix composites are of interest every day due to their lightweight, improved mechanical properties, and increased corrosion resistance. They are used in the aeronautical, aerospace, marine, and automotive industries. A variety of methods can estimate Their corrosion properties. The open-circuit potential studies are also a tool for evaluating the corrosion of composite materials. This research paper focuses on studying open circuit potential determination of the aluminium 7075 alloys reinforced with silicon carbide particulate in differently concentrated sodium hydroxide solutions. The composite materials were prepared by adding 2, 4, 6, 8 and 10 weight percentages of silicon carbide to the aluminium base metal liquid melt metallurgy technique (Vortex method). The silicon carbide used as reinforcement in size range of 50 – 80 µm, which is commercially available. The SiC particulates material is had been preheated to 400°C and introduced into the liquid melt of Al7075 at a rate of 100 g/m, under constant agitating condition using a mechanical stirrer system for 3 to 4 minutes. Rectangular specimens of 2 cm length, 1cm width and 1 mm thickness were used for the experiments. 1sq.cm area of the specimens was exposed to sodium hydroxide medium. Open circuit potential experiments test was conducted using a multimeter and calomel electrode system. The potential observed for 2, 4, 6, 8 and 10% silicon carbide composites were less than the potential of matrix alloy for a range of 30 hours.