Mechanosynthesis of nanocrystalline titanium nitride and its microstructure characterization

Nanocrystalline stoichiometric TiN powder has been prepared by ball-milling the α-Ti powder under N2 gas at room temperature. The α-Ti phase is partially transformed to the transient β-Ti phase and TiN phase is noticed to form after 3 h of milling and nanocrystalline TiN phase is formed after 9 h of milling. Microstructure characterization of unmilled and ball-milled samples characterized primarily by X-ray diffraction employing the Rietveld structure refinement clearly reveals the presence of TiN phase and inclusion of nitrogen atoms in the α-Ti lattice in the way to formation of nitride phase. Transmission electron microscopy image confirms the presence of TiN phase and the size of TiN particles obtained from both XRD and TEM methods of characterization are very close in value (∼13 nm).