Composite materials are extensively employed throughout the defense and aerospace industry due to their superior specific strength and stiffness characteristics, in addition to their immunity to corrosion and ability to reduce fastener counts with net-molded shapes. The vulnerability of composite laminates, however, is that while they have advanced reinforcing fibers running in-plane, their properties are dominated by their binding polymer matrix through-the-thickness. This leads to impact damage, delamination and fatigue susceptibility under certain conditions. We have demonstrated that nanofiber reinforcement can be introduced into the interlaminar region of composites, thereby improving static and dynamic toughness properties as much as ten-fold without affecting weight or thickness. These NAno InterLaminar Scaffolds (NAILS) are customized specifically for each material system to be application-optimized, and can be applied in a roll-to-roll format to composite prepreg.
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Nanoengineered Materials
Nano-scale elements—including synthetic polymer nanofibers, Carbon Nano Tubes (CNT), Boron Nitride Nano Tubes (BNNT), and graphene—can be used to enhance the performance of engineered materials. When dispersed within a polymer nano composite (PNC), packaging for electronic components can be produced that provides superior resistance to extreme temperature, radiation and electromagnetic interference exposure. Veils of nano-scale elements can be incorporated within traditional composite materials as a scaffold between the micron-scale fibers of adjacent plies, to provide interlaminar reinforcement, remove voids, and promote capillary pressure. MDC specializes in the application-specific customization of nanoengineered materials, including selection of optimal chemistry, density, porosity, thickness, and integration mechanism, with the objective of providing uniform, scalable, reliable, and affordable results.
Void Removal (SILC)
Nanofibers can also be introduced into the interlaminar region of composites to reduce voids. Here, the Scaffolds for InterLaminar Capillarity (SILC) serves three primary functions: smoothing the topography of each ply surface; providing an evacuation channel for volatiles to be released; and applying capillary forces between adjacent plies. SILC layers are customized specifically for each material system, and in some cases can also provide interlaminar reinforcement in addition to minimizing voids. SILC is particularly useful for thick laminates, or components with complex geometries such as a high degree of curvature or multiple ply-props. Properly designed SILC can promote internal capillary pressure even greater than that applied by an autoclave, thereby enabling vacuum-only curing in an oven or heated tool using a non-structural mold.