Exploration of glass fiber, alumina, and silicon carbide reinforcements in epoxy hybrid composites: An experimental investigation of physical, flammability, and mechanical properties

The growing demand for weight reduction in automobiles and aircraft to enhance fuel efficiency and reduce COã emissions, in line with global regulations, has driven the adoption of lightweight composite materials. Glass fiber (GF) reinforced polymer composites, in particular, offer a promising solution. This study investigates the influence of Al 2 O 3 /SiC micro-particles (MPs) at varying weight percentages (0–6 wt. %) on the physical and mechanical properties of GF-epoxy hybrid composites, fabricated using the compression molding process followed by the hand layup technique. The composites were evaluated for density, moisture content, dimensional stability, tensile, flexural, impact, and hardness properties per ASTM standards. Scanning electron microscopy (SEM) analyzed tensile and flexural failure mechanisms. Optimal mechanical properties were achieved at 4 wt. % Al 2 O 3 /SiC, with maximum tensile strength (168.02 ± 2.30 MPa), flexural strength (162.09 ± 1.51 MPa), impact resistance (24.2 ± 1.64 J/m), and hardness (77.3 ± 1.70 HSN). These results demonstrate the potential of GF_AS epoxy composites for lightweight structural applications in the automotive and aerospace industries.