Manufacturing of biomorphic (Si, Ti, Zr)-carbide ceramics by sol-gel processing

Biomorphic (wood derived) carbide ceramics with an overall composition in the systems MeC/C (with Me = Si, Ti, Zr) were produced by vacuum infiltration of low viscosity organo-metallic colloidal suspensions into biologically derived carbon templates. After hydrolysis into Me(OH)4-gels, the Me(OH)4-gel/C-templates were submitted to a high temperature pyrolysis/reaction treatment at 1600 °C to promote (i) the polycondensation of the Me(OH)4-gels into the corresponding MeO2-phase and (ii) the carbothermal reaction of the MeO2 with the biocarbon template into highly porous, biomorphic SiC/C-, TiC/C- and ZrC/C-ceramics. The influence of the initial porosity of the biocarbon template on the final phase composition and morphology of the formed biomorphic MeC/C-ceramic composites is analysed.