Slide Image: There are four images connected left to right by arrows. The first image is a photo that looks up toward the canopy of leaves of a group of tall trees. The next three images are electron microscope images, each with a 200 micrometer scale. Nature has provided some outstanding examples of complex, but effective material design for mechanical robustness, such as wood. This can be replicated in synthetic materials using wood as a template. "Biomorphic" silicon carbide can be produced through the controlled pyrolysis of wood to provide a carbon scaffold (second image) for infiltration by liquid silicon. The silicon reacts with the carbon to form silicon carbide (third image). The resulting microstructures are sophisticated cellular structures with unique mechanical properties with high temperature capabilities (>1300ºC) for filters and catalyst supports. Silicon carbide/aluminum composites can be fabricated by re-infiltration of the silicon carbide with molten aluminum (fourth image – far right).
This work is performed in conjunction with the University of Seville and the Polytechnic University of Madrid.
Credit: National Park Service (tree image);
V. Kaul, T. Wilkes, K. Pappacena, K. T. Faber, Northwestern University (electron microscope images)