Wood‐Derived Porous SiC Ceramics by Sol Infiltration and Carbothermal Reduction

Abstract

A new method for transforming wood structures into ceramic by carbothermal reduction of silica and carbonized wood has been developed. Application of this technique allows the preservation of wood microstructures in the ceramic state and the conversion of wood components without constraints in component size. The chosen infiltration technique of silica sol incorporation into carbonized wood structures is examined in terms of sol and wood type, carbonization conditions of the wood, and thickness of the infiltrated carbon body. Ceramization conditions were optimized, and the reaction mechanism is discussed.

Microstructural characterization using orientation imaging microscopy of cellular Si/SiC ceramics synthesized by replication of Indian dicotyledonous plants

“…Though reports are available of the processing of cellular SiC based ceramics or composites from woods, involving graphitization of carbon during pyrolysis at high temperatures in the range of 1600-1800 • C for 4 h, prior to Si infiltration, 9,46 graphitization may also take place during the infiltration itself and the present study does agree with the general model presented by Zollfrank and Sieber 37 -though there is one contradiction. Clear presence of graphite inside the Si grains could be established both by backscattered imaging and by EBSD, the latter confirming presence of graphite.…”

Ice-templated porous alumina structures

“…Cellular ceramics can be engineered to combine several advantages inherent from their architecture [4]: they are lightweight, can have open or closed porosity making them useful as insulators or filters, can withstand high temperatures and exhibit high specific strength, in particular in compression [5]. Typical processing methods include foam or wood replication [6][7][8][9], or direct foaming [10].…”

Processing of polysiloxane-derived porous ceramics: a review

“…Inspired by the early work of Schwartzwalder and Somers [2], many investigations explored the usage of several templates such as wood [52,53], coral [54,55], polymeric foams [56][57][58][59], etc, to prepare porous ceramics for use in a variety of applications [5]. The porous ceramics prepared from polymeric foams and ceramic slurries possess thin struts containing central holes [58].…”