Micro-Architected Carbon Composites

Abstract

Strong, stiff, and lightweight materials are highly desirable in a variety of industries, but this combination has been unavailable in traditional monolithic materials. High stiffness and low-density micro and nano scale lattices have been produced to meet this desire but are highly brittle and unsuitable for mechanical applications. Three lattice topologies with relative density of 20% were produced in a custom polymer and pyrolyzed into carbon lattices. Two different methods of infiltrating an epoxy matrix into these micro-lattices were tested, reaching fill percentages of ~96% and ~99%. Micro-architected carbon composites were created using the superior infiltration method, and all three stages (polymer, carbon, composite) were compression tested to determine the modulus and strength. The infiltration of the epoxy created an interpenetrating phase composite and mitigated the brittle failure mode of the carbon lattice, increasing its strength, stiffness, and toughness. These results are the first step toward characterizing the mechanical properties of a new class of materials: three-dimensional architected carbon composites.