Investigating the Mechanical Characteristics of Coconut Fibre/Eggshell Powder/Alumina Reinforced Epoxy Hybrid Composites

Abstract

The development of hybrid polymer composites reinforced with renewable and waste-derived fillers has been prompted by the growing need for high-performance, sustainable materials. The mechanical behaviour of epoxy-based hybrid composites reinforced with alumina, eggshell powder, and coconut fibre is examined in this work. Tensile, impact, hardness, and wear tests were conducted in compliance with applicable ASTM standards after the materials were manufactured utilizing the hand lay-up method with different reinforcing ratios. With maximum values of 79.80 VHN and a specific wear rate of 0.000438 mm³/Nm, respectively, the results demonstrated that the addition of alumina and eggshell greatly increased hardness and wear resistance. Conversely, composites with higher fibre content exhibited better impact resistance due to improved energy absorption mechanisms, while intermediate formulations with 60% epoxy, 20% coir, 10% alumina, and 10% eggshell demonstrated a balanced combination of strength, toughness, and durability. The results show that appropriate fibre and filler loading optimization can provide lightweight, environmentally friendly composites appropriate for roofing and structural applications, supporting waste conversion and sustainable material development.