Enhancing the Impact Resilience of Subzero Composite Laminates by Novel Recycled Milled Hybrid Fillers

Composites reinforced with fibres have a high specific strength and are very rigid, making them useful in the energy, aerospace, and automotive sectors. Composite constructions are susceptible to internal damage and residual strength loss due to unanticipated exterior impacts in the workplace. Addressing the disposal of composite materials sustainably is another persistent challenge. Low-velocity Impact at room temperature, -20 ^oC and -50 ^oC temperatures, and post-impact flexural (FAI) behaviour of glass/epoxy composite laminates are studied with the inclusion of recycled milled carbon (rmCF), recycled milled Kevlar (rmKF), and hybrid recycled fibres (rmHF) as fillers. Using ultra-sonication and mechanical stirring procedures, the glass/epoxy laminates were enhanced with 3.5% rmC Fillers, 0.375% rmK Fillers, and 0.375% rmH Fillers by weight of epoxy. The impact force, absorbed energy, residual flexural strength, and growth of damage area were used in investigations of surface roughness and hardness and the crash performances to evaluate the reaction of neat glass epoxy and glass epoxy composites loaded with recycled milled fillers to low-velocity impacts at sub-zero temperatures. With a peak force increase of 97.4%, a damaged area drop of 28%, and a reduction of 30.3% and 54.1% in surface roughness, respectively, the rmHF composites outperformed the baseline samples. The residual flexural strength of rmH filler samples was 14.2% more than that of raw glass epoxy composites during LVI testing, as measured in a 3-point bending test conducted at -20 ^oC. Recycled milled filler composite has better impact and FAI characteristics, making it a promising material for load-bearing uses in sub-zero temperatures.