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