Mechanosynthesis of nanocrystalline Ti0.9C0.1N at room temperature and its microstructural aspects

The nanostructured Ti0.9C0.1N has been prepared by ball-milling the elemental stoichiometric powder mixture of Ti and graphite under nitrogen at room temperature. Within 1 h of milling, the α-Ti (hcp) phase partially transformed to metastable β-Ti (cubic) phase and initiation of Ti0.9C0.1N (fcc) phase is noticed. Completely stoichiometric nanocrystalline Ti0.9C0.1N phase is obtained after 5 h of milling. Microstructure characterization of unmilled and all ball-milled powders is made by analyzing their XRD patterns employing the Rietveld structure refinement method. The analysis reveals the inclusion of C and nitrogen atoms into the Ti lattice on the way to formation of Ti0.9C0.1N phase. The inclusion of C and nitrogen atoms in the α-Ti lattice is also confirmed by EDX. The microstructure of ball-milled samples is also characterized by HRTEM. The average size of almost monodispersed spherical particles of Ti0.9C0.1N is ∼4 nm which corroborates the finding of the Rietveld analysis.