Spark Plasma Sintering of high-density fine-grained Y2.5 Nd0.5Al5O12 + SiC composite ceramics

Spark Plasma Sintering (SPS) has been used to produce samples of fine-grained composites Y-2.5 Nd0.5Al5O12 + x wt.% alpha-SiC (x = 1020) with similar to 98-99% density. The microstructure of the composites has been studied, as well as the impact of alpha-SiC particles on the mechanical properties and kinetics of composite sintering. The introduction of the alpha-SiC part has been demonstrated to form a more fine-grained structure and under the given SPS conditions change the sintering mechanism in ceramics. The study has also demonstrated that introduction of alpha-SiC particles into garnet results in formation of internal stress fields, which, in turn, leads to a decrease in the activation energy of sintering of fine-grained composites at high temperatures.