Enhancing Mechanical and Corrosion Properties of Brass Composites with Carbonized Coconut Shell Ash

Abstract

This study investigates the mechanical properties and corrosion behavior of brass (Cu-Zn alloy) reinforced with carbonized coconut shell ash (CSA) composites. The coconut shells were obtained, sun-dried, crushed, carbonized at 500 °C and sieved. The resulting CSA was then incorporated into molten brass scrap, which was first preheated to 950°C. For reproducibility purposes, several samples were prepared with varying CSA weight fraction (0wt%, 5wt%, 10wt%, and 15wt%). The samples were characterized by using metallurgical microscopes to assess their microstructure and homogeneity. The mechanical properties, including: ultimate tensile strength (UTS), hardness, impact energy, and compressive strength, were evaluated. The corrosion analysis was carried out by attaching the respective samples to a holder in the electrolytic streams of the acid and chloride solution in the constructed sand slurry pot using potentio-dynamic polarization. X-ray fluorescence was used to determine the elemental composition of the brass scraps. The results indicated that increased CSA content improved UTS, hardness, and compressive strength. However, a reduction in impact energy was observed. The sample with 15wt% weight fraction of CSA, exhibited the highest UTS (326.32 N/mm²), hardness (281.67 HRB), and compressive strength (198.3 MPa). Nevertheless, sample A with 0wt% weight fraction of CSA, showed the highest impact energy (35.59 J). Corrosion rates varied, with sample A showing the moderate rate of corrosion resistance, sample B is prone to high rate of corrosion, sample C has the poorest corrosion resistance, while sample D exhibited the best overall corrosion resistance. This study demonstrates that CSA reinforcement enhances the mechanical properties of brass composites, making them suitable for various engineering applications.