CaCO₃ derived from eggshell waste for improving the hardness values and wear behavior of composite coating on mild steel via co-deposition

The increased demands for eggs for consumption have large increases in the deposition of eggshells as environmental pollution worldwide and increase high management costs. To reduce the management costs of eggshells, this work attempt was made to utilize eggshells as a source of CaCO₃ for improving the hardness values and wear behavior of composite coating on mild steel. The composite coating was produced using 0, 5, 10, 15, and 20 g CaCO₃-derived eggshell particles. The response surface method was used to determine the influences of applied load, sliding speed, and weight of CaCO₃-derived eggshell particles on the wear behavior. The results have shown that Zn- CaCO₃-derived eggshell particles composite coatings were successfully formed on mild steel. A 90.17% improvement of hardness values was obtained at Zn-20 g CaCO₃-derived eggshell particles. The Zn-20 g CaCO₃-derived eggshell particles sample has a lower friction coefficient. Wear rate increase with the increase in applied load and sliding speed. The optimum condition was obtained at CaCO₃-derived eggshell particles (+ 1), applied load (− 0.35), and speed (− 0.58) with the lowest wear rate of 0.99 mm³/Nm. It has been recommended that the Zn-20 g CaCO₃-derived eggshell particles composite coating of mild steel can be used in areas where wear and roller body are paramount.