Fracture strengths and microstructures of Si₃N₄/SiC nanocomposites fabricated by in-situ process

Si₃N₄/SiC nanocomposites was prepared by in-situ process using commercial phenolic resin. Microstructures were examined by Transmission Electron Microscopy and Scanning Electron Microscopy. The room and high temperature fracture strengths of Si₃N₄/SiC nanocomposites have been studied using the 3-point bending test. The fracture strength of Si₃N₄/SiC nanocomposites with Al₂O₃ and Y₂O₃ doped samples was about 1100 MPa at room temperature. The fracture strength of Si₃N₄/SiC nanocomposites with only Y₂O₃ doped samples was about 1100 MPa at room temperature and 800 MPa at 1400°C. The grain boundary phases formed during sintering process were examined by X-ray Diffraction method.