Processing of cellular ceramics with anisotropic pore structures by infiltr
ation of liquid Silicon into carbonized wood and subsequent reaction to SiC
was investigated. Natural wood of different pore size distribution and com
position was carbonized at 800-1800 degrees C in inert atmosphere resulting
in a one-to-one reproduction of the original wood structure. The carbon te
mplate was converted to SiC by a rapid liquid infiltration-reaction process
at 1600 degrees C. Spontaneous infiltration was achieved by using the cont
inous tracheidal cells in wood as a transportation path for liquid silicon.
beta-SiC formed by solid-liquid reaction at the pore surface exhibits a cr
ystalline texture which may be related to the initial microfibril orientati
on in the cell walls of wood. Depending on the initial cellular microstruct
ure of the various kinds of wood (ebony, beech, oak, maple, pine, balsa) ce
ramic materials of different anisotropic pore structures in the form of pse
udomorphs of the original wood were obtained. (C) 1998 Elsevier Science Lim
ited. All rights reserved.