Édio Pereira Lima

Influence of the Areal Density of Layers in the Ballistic Response of a Multilayered Armor System Using Box-Behnken Statistical Design

Several works have been dedicated to study the ballistic response of multilayered armor systems (MAS), including those using natural fiber composites as second layer. These composites disclosed good ballistic performance, having economic and environmental advantages. In the present work, the objective was to investigate the effect of areal densities of each MAS layer, in the overall performance of a MAS with an alumina ceramic front, a curaua fabric reinforced composite filling, and an aluminum alloy backing the target. Ballistic “backface signature” tests were conducted, varying the areal densities of the MAS layers according to a Box-Behnken design. The results showed a similar influence of the ceramic and aluminum layers in the MAS “backface signatures”, although deformation and failure mechanisms were significantly different. The composite also showed significant participation in the overall MAS performance. Since the composite is cheaper and lighter, a balance minimizing the other layers would be advantageous.

Curaua Non-woven Fabric Composite for Ceramic Multilayered Armors: A Lightweight, Natural, and Low Cost Alternative for KevlarTM

Advanced ceramics have been extensively applied for ballistic protection, when high levels of protection and low weight are demanded. However, their spalling characteristics require the suitable backing materials to collect the fragments generated on the impact. Synthetic fiber laminates, as KevlarTM and DyneemaTM, are currently the most used solutions despite of their high cost and non-sustainable conditions. Therefore, several materials are being studied to replace the synthetic fiber laminates as second layer, including natural fiber composites, which are light, low cost and sustainable materials. Among these, Amazon curaua fiber composites are promising, due to its known high strength and high modulus. In the present work, novel curaua non-woven fabrics polymer composites have been investigated as part of the ceramic armor system. Ballistic tests were performed following NIJ 0101.06 armor standard. The results showed that these composites are promising alternatives to the synthetic fiber laminates as ceramic backing materials.

Niobophosphate Glass as Sintering Additive for Al2O3-YAG

In this study, the following compositions were produced: Al2O3-YAG laser with 2, 4, 6 and 15% by weight of niobophosphate glass (30mol%P2O5-30mol%Nb2O5-20mol%CaO-20mol%CaF2). Sintered discs were characterized by scanning electron microscopy (SEM), X-Ray diffraction (XRD) with the refinement by the Rietveld method and density. The YAG-Al2O3 composite sintered at 1450 °C showed densification of 90%, which indicates the effectiveness of the sintering additive.