ABSTRACT
Snail shells and discarded aluminium components are of low economic values, and are often considered as environmental pollutants. Finding ways of utilizing these supposed wastes is consequently a direct way of creating wealth from wastes. Snail shell particles are known for their hardness, and thus considered as good alloying agent for aluminum based composites. In this project report, the potential of snail shell particles as reinforcement agent in Al-snail shell particulate composites is reported. Snail shell particles of weight fraction ranging from 16 to 48 wt.% and size of 200, 400 and 600 μm were added to aluminium obtained from discarded aluminum pistons and roofing sheets during casting. The microstructures of the composites were examined under optical metallurgical microscope. The tensile strength and hardness were measured, and these properties were optimized using Box Box Behnken experimental design approach. The results showed that, at 48 wt.% and 600 μm particle size, the tensile strength and hardness are maximized to 236 MPa and 48.3 HRF respectively compared to the tensile strength of 92.4 MPa and hardness of 29.2 HRF for the unalloyed samples. These increases are attributed to the distribution of snail shells in the ductile Al alloy matrix. This indicates that both the tensile strength and hardness are significantly enhanced, and can be used as a low cost reinforcement for engineering applications.
