Influence of calcined snail shell particulates on mechanical properties of recycled aluminium alloy for automotive application

Abstract

Nowadays, low-cost particulate reinforced metal matrix composites with improve mechanical properties are highly sought in various industrial and critical engineering applications including automotive and aerospace sectors. Meanwhile, increasing consumption rate of African giant land snail (Archachatina marginata) had been posing disposal challenges of its shells. Therefore, this paper tends to investigates the influence of waste snail shells particulates on the physical and mechanical properties of recycled aluminum- silicon alloy matrix. Different weight proportions i.e. (0 - 7.5) wt% of calcined snail shell particles at an interval of 1.5 wt% were successfully incorporated into Al-Si alloy matrix melted at 750 °C using stir-casting route. The microstructure, physical and mechanical properties of the resulting composites were examined and presented. Microstructural examination shows fairly uniform dispersion of snail shell particles in the aluminium alloy matrix intermingled with aluminium-silicon dendrites. Mechanical properties such as hardness, impact, compressive and tensile strengths increased with increasing addition of calcined snail shell particulate up to 6 wt% while density and elongation decreases. The total equivalent density reduction of 5.4% in composites compared to unreinforced alloy was obtained at 7.5 wt% snail shell addition. The maximum hardness, impact, compressive and tensile strengths obtained are 118±4 HV, 88 J, 552±20 MPa and 211 ± 4.8 MPa equivalent to 21, 25, 19 and 36 percent increase respectively relative to un-reinforced aluminium-silicon alloy. Hence, mechanical and physical properties of Al-Si alloy can be enhanced using calcined snail shell particulates which can widen its application in automotive industries.

Keywords

• metal marix composite
• low-cost reinforcement
• mechanical properties
• stircasting
• automotive and aluminium alloy