Densification and characterization of spark plasma sintered ZrC-ZrO2 composites

ZrC based composites alloyed by nanosized tetragonal 3 mol% yttria stabilized zirconia were produced with spark plasma sintering to >98% of the theoretical density by sintering at 1900 °C under pressure of 50 MPa for 10 min. The volume fraction of stabilized zirconia varied from 25 to 40 vol% in the precursor powder blend. Room temperature hardness and modulus of elasticity of the compacts were in the range reported earlier for similar materials densified by pressureless sintering, while indentation fracture toughness was around 7 MPa m1/2. Structural analysis indicated formation of oxycarbides of various stoichiometries.