Evaluation, tribological examination, and multi‐objective optimization of aluminum‐fly ash‐egg shell composites for sustainability

Abstract This study addresses the technological challenge of enhancing the mechanical and tribological properties of Al 6082 alloy by incorporating fly ash (FA) and eggshell (ES) as reinforcing materials. The objective is to fabricate hybrid metal matrix composites using sand casting, with varying weight percentages of eggshell and fly ash: 4 wt% eggshell with 6 wt% fly ash, 5 wt% eggshell with 5 wt% fly ash, and 6 wt% eggshell with 4 wt% fly ash. The experimental methodology involved designing experiments with response surface methodology (RSM), considering applied load, sliding velocity, and sliding distance as variables. The outcomes showed that the composite with 6 wt% eggshell and 4 wt% fly ash exhibited superior hardness, tensile strength, and impact resistance compared to pure Al 6082 and other composite variations. Additionally, this composite reduced the coefficient of friction (COF) from 0.489 for the base Al 6082 to 0.265. ANOVA based on RSM identified sliding distance as the most influential factor affecting COF. Optimal conditions for minimizing COF were determined to be a 40 N load, 0.215 m/s sliding velocity, and 800 m sliding distance through confirmatory trials. Scanning electron microscopy (SEM) analysis of the worn surfaces provided further insights into the wear mechanisms. The research reveals that integrating the addition of eggshell and fly ash significantly enhances the mechanical properties and reduces the friction of Al 6082, with sliding distance being a critical factor in tribological performance. This investigation is distinctive due to its innovative use of dual reinforcement with fly ash and eggshell, which are abundant, cost‐effective, and rarely employed together in this context. The research thoroughly investigates various reinforcement ratios, providing vital insights into how they affect the composite's properties, particularly in terms of improving tribological properties. Using RSM and ANOVA makes the findings more precise and reliable. The investigation highlights sliding distance as the key factor affecting the tribological behavior of the composites.