Corrosion Studies on Aluminium-7075 Alloy and its Composites by Weight Loss Method

Aluminium 7075 alloy constitutes a very important engineering material widely employed in the aircraft and aerospace industry for the manufacturing of different parts and components. It is due to its high strength to density ratio that it is a sought after metal matrix composite. At sub-zero temperatures, its strength increases, thus making them a useful low-temperature alloy. Here we emphasise on corrosion studies of Al7075 Metal Matrix Composites. The aluminium metal matrix composites (MMCs) are prepared using Silicon Carbide and Graphite. Al-7075 series alloy is used to prepare composites with varied percentage of SiC and hybrid composite (HMMCs) with equal amount of SiC and Graphite by liquid metallurgy technique using vortex method. Specimens for corrosion test were prepared as per ASTM standard of as casted composites. The corrosion studies were carried out for 7 days by weight loss method by immersing the as casted specimens in acid chloride, acid sulphate, acid nitrate and neutral chloride medium at room temperature for 24 hrs and the weight loss is monitored continuously for a weak. The Corrosion rate is measured based on Weight loss of the specimens and it was assessed by plotting graph of corrosion rate against time in hours, using origin-8 software. The studies have revealed that the rate of corrosion is lower in neutral chloride medium when compared to other mediums.