shown in Fig. 4. These grains show the typical core–rim
structure. The core presents higher SiC content than the
rim, proving that liquid-phase sintering proceeds via
solution–reprecipitation mechanism where Al2O3–Y2O3
additive system forms a reactive Al–Y–O rich liquid
phase during densification and grain growth [28].
Furthermore, liquid phase generally appears
well-distributed in both samples. The liquid phase was
identified by means of XRD analysis. X-ray patterns of
C-SiC and T-SiC sintered samples are reported in Fig. 5.
C-SiC sintered sample is composed by hexagonal α-SiC
(polytypes 6H and 4H) as main phase and yttrium