Studies on micro structural characteristics, mechanical and tribological behaviours of boron carbide and cow dung ash reinforced aluminium (Al 7075) hybrid metal matrix composite

摘要

This study focuses on the influence of reinforcements in microstructure, mechanical and tribological properties when compared to the base material (Al 7075). Boron carbide (B4C) and cow dung ash (CDA) were reinforcements by varying the weight percentage from 0 to 10 using two stage stir casting technique. Micro structural analysis and phase identification were investigated by optical microscope, SEM with EDX and XRD respectively. Mechanical and tribological testing was carried out and fracture mechanisms for tensile, impact and wear were analysed. Micro structural images reveal uniform distribution of reinforcements in matrix and XRD confirms the presence of reinforced B4C - CDA particles in the samples. It is concluded that the mechanical and tribological properties have increased while adding B4C - CDA reinforcements yet impact strength has slightly reduced. Dimples, transgranular cleavage facets, cracks and micro ploughing, micro cuttings are revealed from the fractured specimens of tensile, impact and wear respectively.