A novel approach to enhance the mechanical behavior of glass epoxy laminates with sustainable recycled milled fillers

The aerospace, automotive, and energy industries can use fiber-reinforced composites due to their high specific strength and stiffness. However, unexpected external impacts in work cause internal damage and residual strength loss in composite structures. Another ongoing issue is the sustainable management of composite materials' end-of-life. The quasi-static indentation properties of glass epoxy composites are investigated in this study using different kinds of novel filler materials that are recycled from old composite materials: recycled milled carbon (rmCF), recycled milled Kevlar filler (rmKF), and an innovative hybrid filler (rmBF) composed of recycled milled carbon and Kevlar fillers (rmBF). Surface roughness and hardness studies assessed the quasi-static indentation (QSI) response of neat glass epoxy and glass epoxy composites loaded with fillers using indentation force, absorbed energy, residual dent depth, and evolution of damage area. Compared to the baseline samples, the rmCF composites performed exceptionally well, showing a 16% increase in peak force, a 59% decrease in damaged area, and a 6.32% and 22.5% reduction in surface roughness, respectively (Ra and Sa). After QSI tests, rmC filler samples had 26.8% higher residual flexural strength than neat glass epoxy composites in a three-point bending test. Through toughening mechanisms like filler interlocking and bridging, micrographs captured using a scanning electron microscope (SEM) showed that recycled fillers provide a higher level of stiffness, better energy dissipation, less damaged area, and overall improved hardness.HighlightsRecycled milled carbon (rmCF) and Kevlar hybrid fillers (rmKF) have been integrated into glass/epoxy composites.The damage tolerance of glass epoxy composites was as a whole significantly improved by the rmCF integration.The Kevlar fillers' inadequate adhesion and interlaminar shear strength were compensated for by the Hybrid fillers (rmBF).Micrographs taken with a scanning electron microscope (SEM) clearly show the fillers' role in the resistance to damage propagation processes. Influence of recycled milled fillers on the damage tolerance of Glass epoxy composites.image