Paper derived biomorphic porous titanium carbide and titanium oxide ceramics produced by chemical vapor infiltration and reaction (CVI-R)

Chemical vapor infiltration (CVI) is used for producing biomorphic porous TiC ceramics derived from paper. The paper samples are first carbonized in inert atmosphere to yield biocarbon template structures (Cb-template). Subsequently, three routes for converting the Cb-templates into TiC ceramics are studied. The first route includes CVI with TiCl4-H2. The effect of methane as additional carbon source is investigated on the second route (TiCl4-H2-CH4). Finally, a two step CVI process (Route 3), first TiCl4-H2 and subsequent TiCl4-H2-CH4, is performed in order to improve both the grade of conversion of the Cb-template into TiC and the mechanical properties of the resulting porous TiC ceramics. Furthermore, porous TiO2 ceramics are produced by high temperature oxidation of the TiC ceramics in air flow.