Mallinda Inc. — Department of Defense SBIR Phase II: AF222-D029

Description

Although the current ballistic protection material technology meets the desired performance criteria, the major challenge is on-demand manufacturability. The overarching goal of this project is to develop a light-weight customizable material of high impact performance for defense applications such as armor systems. Mallinda’s vitrimer will enable the onsite part production, assembly, repair, and reshaping. The polymer design facilitates the thermally activated covalent bond exchange reaction which allows these agile manufacturability features. Multi-layer armor system is necessary for structural and ballistic protection, minimum deflection, stress transmission etc. To adapt Mallinda’s Vitrimax for this purpose, the commercial resin needs to meet the end-user defined impact performance and process parameters for efficient, cost-effective part production. Targeted properties for vitrimax such as glass transition temperature, Tg < 212 o F, viscosity ~30,000 cP at 158 o F, pot life > 1hr, cure time < 20 min, good fiber affinity will be achieved by adjusting various material and process parameters including the formulation, cure cycle, mixing ratio, additives content, processing temperature, and solvent content. The modified vitrimax will be employed to attain the performance matrices for the composite backing layer of a vehicle armor system. Plain weave S2 glass fiber, ballistic grade aramid fiber, ultra-high molecular weight polyethylene (UHMWPE) will be used as starting reinforcements. Resin content will be optimized in the range of 15 to 40 wt.%. Areal density, water absorption, tensile strength and modulus, flexural strength and modulus, interlaminar shear strength will be the guiding parameters for the composite backing layer. For multi-hit ballistic protection, alumina particle reinforced vitrimer layer will fabricated to serve as a ceramic front layer in the system. 80 wt.% alumina in elastomeric vitrimer layer will be fabricated by compression molding at the vitrimer’s re-processable temperature. Ballistic tests will be performed on composite backing layer as well as multilayered panel using MIL-STD-662 via V50 test. The targeted V50 value for the composite backing layer is at a minimum of 760 m/s for FSP and for the hybrid layer is at a minimum of 900 m/s for API. Visual inspection of the damage, depth of penetration, muzzle velocity, projectile type, distance between the panel and the projectile hit will be investigated for a given areal density-thickness of a panel. Based on the performance, a prototype panel of optimized hybrid layers for a composite armored vehicle (CAV) will be developed. Finally, onsite ability to assembly, reshape and repair will be demonstrated. Vitrimer based material will pave the way to simple on-demand manufacturing processes for composite integral armor (CIA) system. The dynamic material will result in ease of operations and logistics for the Department of Defense (DOD) and ultimately reduce the sustainment cost.