Abstract:The stir casting technique was used to fabricate aluminum 2024 matrix hybrid composites reinforced with SiC (5%, mass fraction) and red mud (5%-20%, mass fraction) particles. The developed composites were characterized by using scanning electron microscopy (SEM) and electron dispersive spectrum (EDS) techniques. Further, Taguchi’s approach of experimental design was used to examine the tensile strength of the hybrid composites (with minimum number of experiments). It was found that the reinforcing particles were well dispersed and adequately bonded in the hybrid composites. The density and porosity of the hybrid composites were reduced with the increase in reinforcement content. The tensile strength of the composites increased with the increase in the red mud content and the ageing time. The developed model indicated that the red mud content had the highest influence on the tensile strength response followed by the ageing time. Overall, it was found that Al2024/SiC/red mud composites exhibited superior tensile strength (about 34% higher) in comparison to the Al2024 alloy under optimized conditions.

Key words: aluminum matrix composites; hybrid reinforcements; tensile strength; red mud; stir casting; statistical analysis; scanning electron microscopy (SEM)