Sintering behavior & microstructure of SPS processed pure 15R-SiAlON polytype

Laboratory synthesized phase pure preformed 15R-SiAlON (SiAl4N4O2) powder devoid of external sintering aid was undertaken for spark plasma sintering. Details of nature of sintering have been pursued. The material is sinterable through solid-state-diffusion though, lattice substitution makes the sintering process more difficult to that of AlN. Elongated grains with clean boundary are observed. Grains exhibit strain contrast, bend contour and array of dislocations displaying deformation in lattice.