In situ synthesis of SiC nanofibers in Al2O3-based ceramics by using cellulose nanofibrils

Abstract The experimental study for in situ synthesis of SiC nanofibers in Al2O3-based ceramics via cellulose nanofibrils (CNFs) is reported herein. The experiment was carried out at 1600 °C under argon/hydrogen gas. The temperature was increased from 240 to 400 °C at a slow heating rate of 1 °C in order to avoid damage to the original morphology of the CNFs after the experiment. The formation of β-SiC in the ceramics matrix was experimentally confirmed using XRD, TEM, and HRTEM analyses. There was an 70% increase in the KIC of the ceramics. This improvement in the fracture toughness of the ceramic is explained by SiC fiber reinforcement. But with the additional content of CNFs in the ceramics increasing, the bending strength of the sample is observed to notably decrease.