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

Si3N4/SiC nanocomposites was prepared by in-situ process using commercial p henolic resin. Microstructures were examined by Transmission Electron Micro scopy and Scanning Electron Microscopy. The room and high temperature fract ure strengths of Si3N4/SiC nanocomposites have been studied using the 3-poi nt bending test. The fracture strength of Si3N4/SiC nanocomposites with Al2 O3 and Y2O3 doped samples was about 1100 MPa at room temperature. The fract ure strength of Si3N4/SiC nanocomposites with only Y2O3 doped samples was a bout 1100 MPa at room temperature and 800 MPa at 1400 degreesC. The grain b oundary phases formed during sintering process were examined by X-ray Diffr action method. (C) 2001 Acta Materialia Inc. Published by Elsevier Science Ltd. All rights reserved.