Mechanical properties of nanocrystalline TiC–ZrC solid solutions fabricated by spark plasma sintering

Nanocrystalline TiC–ZrC solid solutions (TixZr1−xC1−δ) with densification of ~100% have been successfully prepared by spark plasma sintering. Due to the difference in ionic radii of Ti and Zr, the required sintering temperature for single-phase solid solutions exhibits an asymmetric dependence on x, being highest at x=0.7. At a temperature lower than the consolute one, the two-phase solid solution is formed, exhibiting the ability of grain size refinements to nanoscale. Due to the alternate reinforcements and the grain size refinements in TiC–ZrC solid solutions, the mechanical properties of Vickers hardness and fracture toughness are significantly increased when compared to TiC and ZrC.