Effects on microhardness, tensile strength, deflection, and drop weight impact resistance with the addition of hybrid filler materials for enhancing GFRP composites

The work evaluated the usage of various filler materials, namely aluminium oxide (Al₂O₃), magnesium (Mg), and glass powder, in the bidirectional glass fibre reinforced polymer (GFRP) composites. The required samples were fabricated using the hand lay-up technique by varying the filler material proportions from 0%wt. to 7.5%wt., including individual and hybrid mixture combinations. The prepared samples were evaluated for their microhardness, tensile strength, deflection characteristics, and drop-weight impact resistance. It was observed that the optimal addition of individual filler material improved the microhardness and tensile strength more than that of neat composites. In contrast, hybrid compositions at higher proportions exhibited brittleness and lower enactment due to their poor interfacial bonding and particle agglomerations. The deflection characteristics and drop-weight impact tests also showed enhanced stiffness and impact resistance with the addition of hybrid mixtures of filler materials to the composites. The study supports the potential use of adding filler materials to the composites for lightweight structural applications.