PHASE-ANALYSIS AND ROLE OF MICROSTRUCTURE IN THE DEVELOPMENT OF HIGH-STRENGTH PORCELAINS

The flexural strength improved from 154 to 196 MPa at 1450 degrees C w hen the alumina:cordierite ratio was changed from 0 to 4.2, respective ly, in a china clay-sillimanite mix. XRD and microscopic analysis of t he phases that developed with increasing temperature revealed a micros tructure of euhedral grains of sillimanite interspersed with fine mull ite needles and a dense glassy phase wetting the crystalline mosaic st ructure. These contributed to the improved strength. (C) 1998 Elsevier Science Limited and Techna S.r.l. All rights reserved.