Corrosion Studies on Al6061 Alloy Based Hybrid Metal Matrix Composites

Composite materials have gained widespread use in various industries, including aerospace, architecture, automotive, energy, infrastructure, marine and military, owing to their favourable combination of lightweight properties and robust mechanical characteristics. Their corrosion resistance to harsh environments, such as saltwater, acids, and alkaline solutions, further enhances their applicability. This study focuses on investigating the corrosion properties of Aluminium 6061 alloy reinforced with red mud particles. Aluminium 6061 matrix and red mud-reinforced composites are commercially available and widely utilized. Red mud, a by-product of aluminium ore refining, comprises a mixture of iron oxides, silicon, zirconium, titanium, and vanadium. In this research, red mud was employed to reinforce Al6061/alumina/graphite hybrid metal matrix composites, fabricated through the stir casting method with red mud content percentages of 3% and 7%. Cylindrical specimens were meticulously manufactured and machined to ensure uniformity. Subsequently, these specimens were subjected to immersion in concentrated hydrochloric acid for a duration of 96 hours, with periodic observations at 24-hour intervals. The weight of the specimens was recorded after each immersion, followed by drying in an oven for 15 minutes. Corrosion rates were calculated using established corrosion rate formulas. The results demonstrate that an increased percentage of red mud particles in the composites enhances their corrosion resistance compared to the base alloy. The corrosion rate of the alloy exceeded that of the composites. Consequently, this research suggests the practical utility of these composite materials in environments where corrosion resistance is paramount, advocating for the preference of composites over pure alloys.