Formation of nanometric hard materials by cold milling

The fabrication of nanosized, single crystal TiC or TiN powders from ilmenite or TiO₂ within a single low temperature stage is reported in this paper. The titaniferous powders were ball milled for 100 h in a laboratory scale mill with magnesium powder and either graphite or nitrogen. The resultant powders were then subjected to an annealing step at 1200°C. Differential thermal analysis and X-ray diffraction showed that the phases formed within the milling step and underwent grain growth on annealing. Acid leaching of the powders selectively removed the unwanted product phases leaving only the hard material. The final particle size and Scherrer XRD crystallite size were similar after annealing, implying that the particles produced were single crystal.