Synthesis of biomorphic SiC ceramics

Abstract

This paper deals with a new method for producing non-oxide ceramic using wood as a template. Highly porous silicon carbide (SiC) ceramic with woodlike microstructure has been prepared by carbothermal reduction reactions of Tilia wood/TEOS composite at 1873K. Wood specimens were carbonized at 1273K in Ar atmosphere for 2 hour. The porous carbon preform was infiltrated with TEOS (Si(OC(2)H(5))(4)), as a source of silica, without pressure at 298K. The infiltration/annealing processs was repeated up to five times to increase the SiO(2) content in the bionnorphic samples. The morphology of resulting porous SiC ceramics, as well as the conversion mechanism of wood to porous SiC ceramics, have been investigated by mean of scanning electron microscopy (SEM/EDS) and X-ray diffraction analysis (XRD). Experimental results show that the biomorphic cellular structure of wood is preserved after thermal treatment as a porous SiC ceramics. Obtained SiC ceramics consists of beta-SiC with traces of alpha-SiC.