Low temperature mechanochemical formation of titanium carbonitride

The formation of a sub-micron sized powder composed of nanocrystalline alumina and titanium carbonitride of two different stoichiometries during high energy ball milling is reported in this paper. The starting materials were rutile (TiO₂), graphite and aluminium powder. A similar composite with iron was also produced using the mineral ilmenite (FeTiO₃) as the starting material. The powders were ball milled together under a nitrogen atmosphere for 100 h in a laboratory scale mill and subjected to thermal analysis and isothermal annealing at up to 1200°C. X-ray diffraction showed that the phases were formed during the milling step and underwent grain growth and then reaction upon annealing. Differential thermal analysis indicated no residual elemental aluminium after milling confirming that the reaction was complete within the mill.