Titanium nitrides are widely used in manufacturing cermets, cutting tools, decorative, refractory and cover layer for metals and alloys [1–5] because of its desirable properties such as high hardness, high thermal conductivity, high temperature stability and good corrosion resistance. Titanium nitride powders are usually synthesized by direct nitridation of titanium hydride or dioxide, carbon-reduced nitridation of titanium dioxide and self-propagating combustion synthesis [6–8]. All these techniques involve high temperature, and they are not easy to be used to synthesize nano-sized materials.Fine grain titanium nitride powders can be synthesized by ball milling of titanium with boron nitride, nitrogenous organic solution, nitrogen gas or ammonia gas at room temperature [9–12]. Such obtained titanium nitride powders usually have some impurities,which are hard to remove. It was reported that the nitridation of elements like Si, Fe and Ti is more easily to occur in ammonia rather than in nitrogen [13,14]. However, milling titanium in flowing gas involves a special design that has some technical difficulties.In this letter, a novelty simple method for nano-sized titanium
nitride synthesis is reported. It is found that nano-crystalline titanium nitride can be prepared by reactive ball milling of titanium powders and urea at room temperature. This milling process avoids introducing ammonia or nitrogen gas, and the impurities can be removed simply by ethanol washing.