Simultaneous Synthesis of Titanium Carbide-Alumina from Woody Materials by Self-Propagating High Temperature Synthesis

摘要

In order to prepare simultaneously TiC-Al_2O_3, and to suppress formation of carbon defects in TiC prepared from self-propagating high temperature synthesis (SHS) of woody materials with Ti, the reaction of each woody material with Ti and Al was investigated and compared with their reaction with Ti only. The reaction of Japanese cedar (Cryptomeria japonica D. Don) bark, cellulose or lignin as the woody materials, with Ti alone or Al-containing Ti powder was examined under the conditions favorable for the SHS reaction. The effectiveness of Al in reducing the amount of carbon defects in the TiC was confirmed by performing the SHS reaction with and without Al. The carbon and oxygen in the woody materials reacted with Ti and Al to yield TiC and alpha-Al_2O_3, respectively. The amount of carbon defects in cellulose-derived TiC decreased with increasing aluminum, whereas lignin-derived TiC hardly changed in that regard. Because added aluminum reacts preferentially with oxygen in the woody material, it is guessed that oxygen which it takes to remove carbon atom from the TiC lattice is used up.