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

[Display omitted] •YAG + (10, 20) wt.% α-SiC high-density ceramics obtained by SPS.•YAG + α-SiC ceramics have a more fine-grained structure than pure garnet.•The optimal sintering temperature of YAG + SiC ceramics is lower than that of garnet.•Introduction of α-SiC particles creates internal stress fields in garnet.•Introduction of α-SiC particles results in lower sintering activation energy of garnet. Spark Plasma Sintering (SPS) has been used to produce samples of fine-grained composites Y2.5Nd0.5Al5O12 + x wt.% α-SiC (x = 1020) with ∼98–99% density. The microstructure of the composites has been studied, as well as the impact of α-SiC particles on the mechanical properties and kinetics of composite sintering. The introduction of the α-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 α-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.