Synthesis mechanism and sintering behavior of tungsten carbide powder produced by a novel solid state reaction of W2N

Nanosized WC powder was synthesized by solid state reaction between tungsten nitride (W2N) and carbon black. The reaction path and the phase evolution during the synthesis were studied. It was found that W2N firstly decomposed to tungsten metal in the middle stage of synthesis, and then it reacted with carbon black to form W2C and WC in sequence. Using this WC powder as the starting material, binderless WC hardmetals were prepared by hot pressing, and the microstructure and mechanical properties of the material were investigated.

► Nanosized WC powder was synthesized by solid state reaction between tungsten nitride (W2N) and carbon black.
► W formed by W2N decomposition at 850 °C showed a fine particle size of less than 20 nm.
► Nanosized W caused a great enhancement in its reactivity, thus reducing the carburization temperature.