HIGH-TEMPERATURE DEFORMATION OF CORDIERITE GLASS-CERAMIC SIC PLATELETCOMPOSITES/

Composites based on barium-containing cordierite glass-ceramic matrice s reinforced with 20 and 30 vol% SiC platelets were fabricated by hot- pressing. The ceramed specimens were tested in compression at 1000, 12 00 and 1300 degrees C in air, parallel and perpendicular to the hot-pr essing direction. Compressive fracture stresses up to 460 MPa were rec orded at 1000 degrees C. Lower stresses were observed at 1200 and 1300 degrees C. The compressive stress decreased with increase in the SIC platelet content and with the compressive direction being parallel to the hot-pressing axis. The mechanical behaviour at high temperatures w as related to the presence of a residual glassy phase within the cordi erite matrix, as well as to the mode of the crack nucleation within th e composites.