Journal of Materials Science, Vol.51, No.14, 7008-7015, 2016
Formation of submicrometer titanium carbide from a titanium dioxide encapsulated in phenolic resin
A novel synthesis process has been developed to produce high-purity and submicrometer titanium carbide powders from a titanium dioxide encapsulated in phenol resin. The precursor powders were produced by coating titanium dioxide powders with phenolic resin shells. Then the precursor powders were roasted at various temperatures from 1373 to 1873 K for 2 h in a flowing Ar atmosphere. The decomposed carbon from phenolic resin could be used to reduce TiO2. X-ray diffraction, field emission scanning electron microscope, and thermogravimetric and differential thermal analyses were employed to characterize the phase composition, microstructure, and reaction mechanism. The phenol resin was decomposed completely into pyrolytic carbon below 1200 K. The pyrolytic carbon with high activities deposited on the surface of TiO2 powders evenly, which formed carbon shells and provided a close contact with TiO2 particles. gamma-Ti3O5, lambda-Ti3O5, Ti2O3, TiC (x) O (y) , and TiC were continuously formed during the carbothermic reduction. It is found that the titanium carbide powders with a lattice parameter of 4.311 were finally synthesized at 1873 K when the molar ratio of titanium dioxide to phenolic resin was 1:0.6. The particle size of the obtained titanium carbide powders was about 0.4 mu m.