Assessment on morphological and mechanical properties of silicon nitride and goat dung ash reinforced Al-Fe-Si alloy hybrid composites

Abstract

For the past few decades, global goat populations exceeds the world population growth especially in Africa and Asia. Because of this, the bio-waste has been increasing drastically. So, this research aims to utilize the excess goat dung as a reinforcement material for the production of a sustainable composite material with enhanced morphological and mechanical properties. The fabricated hybrid composites consist of Al8011alloy as a matrix material, Goat Dung Ash (GDA) and Silicon Nitride (Si3N4) as a reinforcement particles with various proportions from 0% to 10%. Microstructural analysis was performed to estimate the uniform distribution of reinforcement particles. The inclusion of GDA particles along with the Si3N4 particles increased tensile, flexural, and hardness strength with a minor reduction in impact strength (+21.8%, +7%, +62% and −5.5%) when compared with the unreinforced alloys. The transformation of ductile to brittle phase, clustering, crack propagations, necking, dimples, and cleavage facets were inspected in the fractured specimens. The incorporation of an optimal combination of Si3N4 and GDA reinforcement particles results in fine grain structure which restricts the dislocation moments during the action of external load and also prevents the propagation of slip. Similarly, the strong interfacial bonding and adhesion between the soft ductile Al8011 and the Si3N4/GDA reinforcement particles are attributed to the composites’ strengthening process. This research work proves that the use of bio-waste in the fabrication of composites has the potential benefit in enhancing the morphological and mechanical properties.