Thermal and Phase Evolutions of As-Milled Powders Fabricated by Mechanical Alloying in the TiH2-C System
Nano-TiC powders were fabricated for mechanical alloying (MA) by shaker mill using the TiH2 powders mixed carbon powder. For mechanical alloying, titanium hydride was easily breaking alloy and easily decomposed titanium particles and hydrogen gas. The decomposition titanium powders in TiH2 powders were very fine particle size and unstable phase. And it easily reacted to carbon ;(TiH2 + C TiC + H2). The effects of mechanical allyoing, morphology, phase and particle size were evaluated with X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), TG/DTA and particle size analyzer. As-milled powders for 10 hours were successfully synthesized powders of TiC phase, mean particle 300nm size. And as-milled powder for 1 hour was included unstable phase, was annealed for 1 hour at 400°C-1300°C in 1x10-3torr vacuum atmosphere. Unstable phase was changed to recrystallize phase by heat treatment. After heat treatment for 1hour using as-milled powders, it was included many types of titanium oxide at temperature below 1000°C, was formed single phase of TiC at temperature over 1000°C.
Hyung Sun Kim, Yu Bao Li and Soo Wohn Lee
S. Y. Bae et al., "Thermal and Phase Evolutions of As-Milled Powders Fabricated by Mechanical Alloying in the TiH2-C System", Materials Science Forum, Vols. 510-511, pp. 366-369, 2006