Spark Plasma Sintering of Binderless n-WC and n-WC- X (X=Nb, Re, Ta, Ti, B, Si)

Nano sized tungsten carbide (n-WC) compacts with and without grain growth inhibitors were synthesized by Spark Plasma Sintering (SPS) with different heating rates. The microstructure and mechanical properties of the various samples were compared. Grain growth inhibition effects increased in the order Nb>Re>Ta>Ti and with increasing heating rate. Addition of Si and B increases grain growth, but suppresses the formation of the brittle semi carbide (W 2 C) phase. Using the WC-X phase diagram and the sintering rate curves, we try to generalize the effect of various grain growth inhibitors on the sintering of n-WC.