Effect of Various nano fillers on ballistic impact behaviour of STF- based hybrid fibre metal laminates

The developers of protective materials face the challenge of meeting rigid requirements for materials used in armoured vehicles, which must have multi-layered architectures, strength, stiffness, lightweight characteristics, and high durability. The study examined the ballistic behaviour of hybrid fibre metal laminates made of Kevlar and basalt treated with STF (shear thickening fluid) and saturated with different nano fillers such as aluminium oxide (Al 2 O 3 ) and silicon dioxide (SiO 2 ). AA7075-T6 was used as the stacking material in fabricating the HFML (hybrid fibre metal laminate). PEG-400 (polyethylene glycol) and silica particle-based STF properties were analysed through various tests like FTIR, XRD, and rheological characterization. When subjected to external stress, the Non-Newtonian STF undergoes a unique phase transition from liquid to solid. The tests show that achieving the desired shear thickening behaviour requires careful selection of solid particles, focusing on their size, shape, and surface properties. The STF-treated fibres underwent puncture resistance tests before fabricating the laminates, with fibres containing STF showing significant improvements. The fabrication process involves four layers of Kevlar and four layers of basalt fibres using epoxy resin with AA7075-T6 as the stacking material, arranged in an alternating sequence of Kevlar and basalt fibres. The ballistic performance of the laminate was thoroughly analysed with the support of SEM micrographs, and the inclusion of shear thickening fluid demonstrated a notable improvement in energy absorption.