ABSTRACT
The development and characterization of Al-3.7%Cu-1.4%Mg/Periwinkle shell ash particulate composites using periwinkle ash as reinforcement has been carried out. The periwinkle ash was used in the production of MMCs ranging from 5 to 30% at an interval of 5% addition, using double stir casting method. The periwinkle shells were characterized using X-ray fluorescent (XRF) that revealed CaO, SiO2, Al2O3, MgO, and TiO2 as major compounds. The microstructural analyses of the composites produced were studied using X-ray Diffractometry (XRD), Scanning Electron Microscopy (SEM). The physical properties (density and porosity) and mechanical properties such as tensile strength, impact energy and hardness values of the composites developed were determined. The microstructure obtained revealed a dark ceramic (reinforcer) and white metallic phases. The results of the mechanical properties tests revealed that, the addition of periwinkle ash increased the hardness of the composites produced for all additions from 55.45 HRF at 0wt% to 87.75HRF at 30wt% progressively. While the yield strength and ultimate tensile strength of the composites produced increased from 115.56 N/mm2 and 153.75 N/mm2 at 0wt% to 151.60 N/mm2 and 202.45 N/mm2at 25wt% PWAp respectively. Thereafter, the yield strength and ultimate tensile strength dropped to 149.75 and 190.58 at 30wt% PWAp respectively. However, Impact energy of the composites produced decreased from 10J at 0wt% PWAp to 4.80J at 30wt% PWAp. These increases in strength and hardness values of the developed composites can be attributed to the proportion and uniform distribution of the hard and brittle ceramic phases in the ductile metal matrix. The density of the developed composites decreased with wt% additions of PWA particles. These results show that improved properties of Al-Cu-Mg alloy are achievable using PWA particles as reinforcement up to a maximum of 25wt%.