Effect of Firing Temperature on Bending Strength of Porcelains for Tableware

Abstract

Porcelains for tableware in the quartz–feldspar (sericite)–kaolin system were investigated to study the effect of firing temperature on the bending strength. The maximum bending strength of a body was attained at about 75°C below the temperature of complete sintering; therefore, its apparent porosity and the total porosity were almost 0% and 8.0%, respectively. Control of the finely dispersed, round, and isolated pores in the body was found to be necessary to attain strengthening of the body despite its relatively large porosity, and at the same time it was important that a large amount of fine quartz particles remain undissolved. Furthermore, a dense layer, formed close to the surface, was observed to strengthen the body more than that expected from its relative density when the body was fired above 1200°C.