Fabrication and comparison of interlaminar fracture toughness behaviour of glass epoxy composites with recycled milled Kevlar-carbon hybrid fillers

Current research uses a novel recycled milled carbon (rmCF), recycled milled Kevlar (rmKF), and innovative Hybrid fillers (rmHF) of both to increase glass/epoxy composite laminate delamination resistance. This study examines how crack propagation and fibre orientation affect laminated composite delamination fracture toughness. Recycled milled Fillers in the interlayer increase stiffness, delamination resistance, and fracture toughness by increasing the energy needed to crack the interlaminar domain. Here, Mode I, Mode II, and Mixed Mode (I/II) with <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mrow> <mml:mfrac><mml:msub><mml:mi>G</mml:mi> <mml:mi>I</mml:mi></mml:msub> <mml:msub><mml:mi>G</mml:mi> <mml:mrow><mml:mi>I</mml:mi> <mml:mi>I</mml:mi></mml:mrow> </mml:msub> </mml:mfrac> </mml:mrow> </mml:math> = 25 %, 50 % and 75 % were studied for four different Interface fibre orientations. It appears [0₆/90₂/0₆] increased delamination toughness. Adding the novel recycled milled fillers improved delamination resistance. Among the three fillers, rmCF increased fracture toughness by 271 % and rmHF and rmKF composites had 220 % and 182 % higher fracture toughness. The synergy compensated for Kevlar's lower fracture toughness in the hybrid (rmHF). SEM analysis of fractured surfaces revealed crack deflection, individual debonding, and filler/matrix interlocking, all of which increase fracture toughness on different levels.