Biomorphic TiN/C ceramics prepared by reduction-nitridation of charcoal/titania composite

Porous titanium nitride ceramics with a biomorphic microstructure were manufactured at 1400°C by carbothermal reduction and nitridation of charcoal/titania composites under high concentration nitrogen atmospheres. These composites were prepared from beech-derived charcoal impregnated with titania sol by vacuum/pressure infiltration process. The formation mechanism of TiN was analyzed. The results show that the nitridation is based on gas-solid reaction among TiO (s), N₂ (g), C (s) or CO (g). Under higher nitrogen pressure, the nitridation reaction was complete and porous TiN/C ceramics obtained. The phase composition and microstructure of as-obtained porous TiN/C ceramics were characterized by X-ray diffraction and scanning electron microscopy. Experimental results show that the resultant porous TiN/C ceramic had the same external and internal forms of the original wood that consists of cubic phase TiN.