Phase homogeneity of Si$_3$N$_4$-based ceramic materials produced by spark plasma sintering

Ceramics obtained by spark plasma sintering of powder compositions of Si$_3$N$_4$ was studied by the method of layer-by-layer X-ray diffraction analysis. The effect of carbon diffusion in the surface layers of the sintered ceramics from the graphite mold was observed. The homogeneity of the ceramic phase composition along the depth of the sample was shown. Therefore, a uniform distribution of the temperature field inside the sintered sample was concluded.