Young's modulus and mechanical strength of porcelain at the firing in the cooling stage

Abstract

Young's modulus and mechanical strength of alumina-enriched porcelain (30% kaolin and clay, 25% Al 2O 3, 30% feldspar, 15% chamotte; 19% and 0·8% total amount of quartz and cristobalite impurities respectively) were measured in the cooling stage of firing (5°C/min). It was confirmed that β → α transformation of quartz is a source of the microcracks and the same influence on the Young's modulus and strength had the β → α transformation of cristobalite: the sharp minimums of Young's modulus at 570 and 280°C were discovered. Mechanical strength increased transienlty after β → α changes.