Impact properties of kenaf Fibre/X-ray films hybrid composites for structural applications

Most existing designs of high velocity impact resistant materials are either heavy or expensive, so in markets the demand for lighter and cheaper materials is always on the rise. The aim of this work to investigates the effect of different projectile shape and impact velocities on the energy absorption and compression after impact of kenaf/X-ray/epoxy hybrid composites. Kenaf fibre treated with NaOH solution and perforated X-ray films were chosen as a reinforcement in the epoxy matrix to fabricate hybrid composites. The hybrid composites were fabricated using conventional hand lay-up method followed by compression moulding and were subjected to high velocity impact tests using a single stage gas gun. The pressure settings of the gas gun were varied as follows: 20 bar, 30 bar, 40 bar and 50 bar, while the projectiles used were of three types: blunt, hemispherical and conical ones. After the high velocity impact tests, the composites underwent dye penetration inspection and were subjected to compression after impact tests. The obtained results revealed that the hybrid composites subjected to high velocity impact with hemispherical projectile exhibited the highest energy absorption, compared to the conical and blunt geometry. On the other hand, the hybrid composites subjected to hemispherical projectile impact possess the lowest residual strength compared to conical and blunt geometry. The dye penetration test as well as the visual inspection also revealed that the hemispherical projectile produces the biggest damage compared to the other two projectile types. We concluded that developed kenaf/X-ray/epoxy hybrid composites suitable for ballistic applications. (C) 2019 Brazilian Metallurgical, Materials and Mining Association. Published by Elsevier Editora Ltda.