Effect of Ti(C,N) Content on Microstructure and Properties ofPressureless Sintered Ti(C,N)/ZrO₂ Ceramic Composites

Ti(C, N)/ZrO₂ ceramic composites were prepared by pressureless sintering with Y₂O₃ stabilized nano ZrO₂ powder, TiO₂ powder, TiN powder, carbon black and water-soluble phenolic resin as raw materials. The effects of Ti(C, N) mass fraction (25%-40%) on the microstructure and properties were studied. The results show that the Ti(C, N)/ZrO₂ ceramic composites consisted of t-ZrO₂ and Ti(C,N) phases. The Ti(C, N) particles agglomerated gradually with increasing Ti(C,N) content, while distributed relatively evenly when the Ti(C, N) mass fraction increased to 40%. With increasing Ti(C, N) phase content, the open porosity of the ceramic composites increased first and then decreased, and the hardness, flexural strength and fracture toughness decreased first and then increased. When the mass fraction of Ti(C, N) was 40%, the ceramic composites had the best comprehensive performance with the open porosity of 0.73%, the hardness of 14.4 GPa, the flexural strength of 354 MPa and the fracture toughness of 5.8 MPa·m^1/2.