Commercial zirconium carbide (ZrC) powder is consolidated by Spark Plasma Sintering (SPS). Processing temperatures range from 1650 to 2100 °C. Specimens with various density levels are obtained when performing single-die SPS at different temperatures. Besides the single-die tooling setup, a double-die tooling setup is employed to largely increase the actual applied pressure to achieve higher densification in a shorter processing time. In order to describe the densification mechanism of ZrC powder under SPS conditions, a power-law creep constitutive equation is utilized, whose coefficients are determined by the inverse regression of the obtained experimental data. The densification of the selected ZrC powder is shown to be likely associated with grain boundary sliding and dislocation glide controlled creep. Transverse rupture strength and microhardness of sintered specimens are measured to be up to 380 MPa and 24 GPa, respectively. Mechanical properties are correlated with specimens’ average grain size and relative density to elucidate the co-factor dependencies.

The densification behavior of zirconium nitride powder is investigated for various temperature and pressure conditions imposed by spark plasma sintering and high voltage electric discharge consolidation techniques. The crystal structure, chemical composition, porosity, and grain size of the powders and processed specimens are analyzed by X-ray diffraction, scanning electron microscopy, and energydispersive X-ray spectroscopy. The outcomes of the two considered consolidation techniques are comparatively assessed. Vickers micro-hardness of the processed ZrN specimens is investigated, and hardness dependence on porosity is analyzed. The densification mechanism of ZrN consolidated by spark plasma sintering is revealed by applying the constitutive equation of the continuum theory of sintering, and it turns out to be a similar mechanism to hot pressing. Application of the sintering constitutive equations shows that the mechanism of ZrN densification by high voltage electric discharge consolidation method depends on the magnitude of the applied voltage.

Two methods of compacting dry poly-and nanodisperse powders into compacts of a complicated shape with uniform density distribution in the volume have been developed: pressing under powerful ultrasonic action and collector pressing by the control of friction forces redistribution. Experimental measuring and simulation of the process of deformation of a powder body by different methods show that in the case of ultrasonic pressing, the dispersion of the density distribution has decreased by 20%, and the relative differential of density along the pressing height has decreased by 35% as compared to the case of the conventional uniaxial pressing. Collector pressing allows reducing the dispersion of the density distribution (has decreased by a factor of 10), while the relative density differential along the green compact height has decreased by 60%.

The uniaxial compaction of dry ceramic nanopowder under powerful ultrasound action is described. The description of nanopowder compaction using a dimensionless equation allows the determination all of the basic pressing parameters to optimize the coefficients of die-wall, interparticle friction, and springback. As a result, a homogeneously dense, unstrained green compact is formed.

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