Microstructure and mechanical properties of silicon nitride–titanium nitride composites prepared by spark plasma sintering

Si3N4–TiN composites were prepared by spark plasma sintering (conventional sintering (SPS1) and in situ reaction sintering (SPS2)). Homogeneous distribution of equiaxed TiN grains in Si3N4 matrix results in the highest microhardness (21.7 GPa) and bending strength (621 MPa) of sample SPS1 sintered at 1550 °C. Dispersion of elongated TiN grains in Si3N4 matrix results in the highest fracture toughness (8.39 MPa m1/2) of sample SPS2 sintered at 1300 °C.