Properties and consolidation of nanocrystalline NbSi2–SiC–Si3N4 composite by pulsed current activated combustion

A dense nanocrystalline 5NbSi2–SiC–Si3N4 composite was synthesized by the pulsed current activated combustion synthesis (PCACS) method within 4 min in one step from mechanically activated powders of NbC, 4NbN and 14Si. A highly dense 5NbSi2–SiC–Si3N4 composite with a relative density of up to 98.5% was produced under the simultaneous application of a pressure of 60 MPa and an electric current. The average grain size and mechanical properties (hardness and fracture toughness) of the composite were investigated.