Synthesis and mechanical behaviour of green metal matrix composites using waste eggshells as reinforcement material

Abstract

Chicken eggshell (ES) is an aviculture by-product that has been listed worldwide as one of the worst environmental problems. The effective utilisation of ES biowaste is strongly encouraged in our society due to environmental and economic reasons. The aluminium alloy (AA) 2014/5 wt% carbonised ES metal matrix composite used in this study was fabricated by electromagnetic stir casting technique at parameters of 12 A (current), 180 s (time) and 700°C (matrix pouring temperature), respectively, and immediately extruded on universal testing machine at 60 MPa using cylindrical H13 tool steel die coated with graphite to avoid upper flow of ES particles and to improve wettability of carbonised ES with AA2014 alloy. Microstructures of composites show uniform distribution of carbonised ES particles. Density and overall cost of the metal matrix composite decreases 3.57% and 5%, respectively, when carbonised ES particulate is added 5% by weight. Tensile strength, hardness, toughness and fatigue strength of AA2014/5 wt% carbonized eggshell composite were also measured. Results show an improvement in these mechanical properties with addition of ES in the matrix alloy.