In-situ synthesis of FexSiy phases and their effects on the properties of SiC porous ceramics

Abstract SiC ceramics are one of the primary ceramic materials with the limitless applications in the fields of aerospace, energy, and semiconductors. However, insufficient strength and toughness are the fatal weakness for ceramic materials, especially for SiC porous ceramics with high-porosity. To investigate the effects of Fe x Si y phases on SiC porous ceramics, in this work, Fe x Si y reinforced SiC porous ceramics were synthesized at 1500 °C-1600 °C for 4 h, with industrial silicon carbide, iron oxide and activated carbon as raw materials. The X-ray diffractometry (XRD), scanning electron microscope (SEM), strength testing, oxidation resistance testing, and thermal shock testing were used to study the effects of the Fe x Si y reinforcement on a few key properties of the SiC porous ceramics. The results showed that when a small amount of Fe 2 O 3 was added ( w (Fe 2 O 3 +C) = 23.4%), the cold compressive strength reached 8.8 MPa, and the apparent porosity increased by 10%. The thermal performance and oxidation resistance of the porous ceramics also performed excellently. Meanwhile, the possibility of the Fe x Si y as a reinforcement for SiC ceramics was confirmed.