Ballistic comparison between epoxy-ramie and epoxy-aramid composites in Multilayered Armor Systems

The ballistic protection against high-energy projectiles, such as the 7.62 mm, is more efficiently performed by means of multilayered armor systems (MAS). A MAS might be composed of a ceramic front, followed by a fiber/fabric composite as intermediate layer, and a ductile metal back layer. In a previous investigation, a MAS with intermediate layer of epoxy composite reinforced with 30 vol.% of ramie fabric was ballistic tested against 7.62 mm ammunition and compared to MAS with Kevlar (R) (aramid fabric laminate) as intermediate layer. Both MAS met the standard requirements, but a significant cost reduction favored the ramie fabric composite. In the present work, two other related epoxy composites, one reinforced with raw ramie fibers and other with aramid fabric layers, are investigated as MAS intermediate layer. The objective is to achieve similar ballistic performance with more economical and/or environmentally friendly materials. The results indicate that both new composites met the requirements with comparable ballistic performance as the previously investigated ramie fabric and Kevlar (R). Moreover, the ramie fiber composite MAS was the least expensive, among all of them, being 14% cheaper than the previously studied ramie fabric composite MAS. (C) 2018 Brazilian Metallurgical, Materials and Mining Association. Published by Elsevier Editora Ltda.