Densification of the eggshell powder by spark plasma sintering

Abstract

Chicken eggshells (eggshells) are the bio-waste produced during day-to-day egg consumption by humans. The eggshell contains calcium carbonate (CaCO3) along with several other elements such as Si, Mg, K, P, Na, etc., which enables its application for human bio-implants. Our research work aims to practically implement the eggshell powder as the bio-implant, for which, the study of the densification behavior of the eggshell powder is required. Hence, the present paper represents the densification behavior of the crystalline eggshell powder by spark plasma sintering. The eggshell powders were irregular in shape with a wide particle size distribution. The eggshell powder was sintered at six varying temperatures, i.e., 250 °C, 500 °C, 750 °C, 850 °C, 900 °C, and 1000 °C. The consolidated samples were characterized through SEM, FTIR, and XRD analysis, and the optimum spark plasma sintering temperature was determined. The consolidation of eggshells at 850 °C not only avoids the calcination process (due to the application of pressure) but gives optimum density and hardness making it an optimum condition for consolidating eggshells into compacts.