Simultaneous pulsed current activated combustion synthesis and densification of NbSi_2-SiC composite

摘要

Dense ultrafine NbSi_2SiC composite was synthesized by the pulsed current activated combustion synthesis (PCACS) method within 3 min in one step from mechanically activated powders of NbC and 3Si. Simultaneous combustion synthesis and densification were accomplished under the combined effects of a pulsed current and mechanical pressure. Highly dense NbSi_2-SiC composite with relative density of up to 97 percent was produced under simultaneous application of a 60 MPa pressure and the electric current. The average grain size and mechanical properties (hardness and fracture toughness) of the composite were investigated.