SiC-Based Ceramics from Naturally-Derived Scaffolds K. T. Faber (PI), Northwestern University, DMR-0244258

1. low high SiC-Based Ceramics from Naturally-Derived ScaffoldsK. T. Faber (PI), Northwestern University, DMR-0244258 Biomorphic silicon carbide is produced by the controlled pyrolysis of wood to provide a carbon scaffold for infiltration by liquid silicon. The silicon reacts with the carbon to form silicon carbide. The resulting microstructures are sophisticated porous structures with unique mechanical and thermal properties and high temperature capabilities (> 1300ºC). For applications which involve extreme thermal excursions, such as heat exchangers or catalyst supports, thermal conductivity should be well characterized. Object-oriented finite element (OOF) analysis is used to assess the thermal flux across these complex solids. The microstructure, the finite element mesh, and the resulting heat flux profile are superimposed in the above figure. The large channels serve to impede heat flow. These are compared to experimental thermal conductivity measurements (below) which correlate well with the reduced in-plane (transverse) conductivity. This work is performed in conjunction with the University of Seville and the Polytechnic University of Madrid.

2. SiC-Based Ceramics from Naturally-Derived Scaffolds:The World Materials NetworkK. T. Faber (PI), Northwestern University, DMR-0244258 A critical part the World Materials Network Program is the interchange of ideas among various collaborators. Although the internet provides an instantaneous and effective communication network, it cannot replace face-to-face learning. Student exchange of Northwestern students included Vikram Kaul to the University of Seville (shown here in a parting lunch in a Seville café) and Thomas Wilkes to the Polyechnic University of Madrid. Ranier Sepúlveda Ferrer and Joaquín Ramírez Rico from the University of Seville each visited Northwestern. In addition to the cultural exchange, these visits are key in transferring the processing technology for biomorphic silicon carbide from Seville to Northwestern and composite processing methods from Northwestern to Seville.