Effects of eggshell on the microstructures and properties of Al–Cu–Mg/eggshell particulate composites

The effects of eggshell particles (ES) on the microstructures and properties of Al–Cu–Mg/ES particulate composites have been studied. A total of 2–12 wt.% ES particles were added. The microstructures of the Al–Cu–Mg/eggshell particulate composites produced were examined by a scanning electron microscope with energy dispersive spectrometer (SEM/EDS). The physical and mechanical properties measured included: density, tensile strength, hardness values and impact energy. The results revealed that the tensile strength increased by 8.16% at 12 wt.% uncarbonized ES and 14.28% at 12 wt.% carbonized ES, the hardness values increased by 10.01% at 12 wt.% uncarbonized ES and 25.4% at 12 wt.% carbonized ES with decrease in the density by 6.50% at 12 wt.% uncarbonized ES and 7.4% at 12 wt.% carbonized ES. The impact energy decreased by 23.5% at 12 wt.% uncarbonized ES and 24.67% at 12 wt.% carbonized ES particles, respectively. These increases in strength and hardness values are attributed to the distribution of hard phases of the ES particles in the ductile Al–Cu–Mg alloy matrix. These results showed that using the carbonized eggshell as reinforcement in the Al–Cu–Mg alloy gives better physical and mechanical properties as compared to uncarbonized ES particles. Hence addition of ES particles upto 12 wt.% can be used as a low cost reinforcement for the production of metal matrix composites for engineering applications.