High-Hardness Lightweight Body Armor

Current Enhanced Small Arms Protective Insert (E-SAPI) plates are made from hot-pressed boron carbide (B4C), which offers a favorable combination of high hardness and light weight. As threats continue to evolve, however, armor systems must also evolve to defeat the threats. Unfortunately, this typically involves increasing the weight of the armor system, which inhibits natural movement and decreases maneuverability for the wearer. Ultramet proposes to build upon its success with fiber-reinforced silicon carbide (SiC) composite armor and apply the lessons learned to an analogous B4C-based composite system. In the previous work, which was for a 7.62-mm APM2 threat, Ultramet’s carbon fiber-reinforced SiC composite backing structure with a thin monolithic SiC strike face outperformed fiber-reinforced ceramic matrix composites (CMCs) without a strike face as well as thick, monolithic SiC. In this project, Ultramet will use its melt infiltration process to fabricate fiber-reinforced B4C composites and combine them with a thin, monolithic B4C strike face to achieve superior ballistic protection compared with state-of-the-art monolithic B4C. Because high-strength carbon fibers are less dense than B4C, incorporating carbon fibers into the CMC will decrease the areal density while increasing the strength and toughness of the structure. This will improve the ballistic protection and improve the multi-hit capability of the composite armor system. The strike face materials to be investigated will also include ultrahard materials with hardnesses greater than that of diamond.