Abstract
A whiteware body composition containing 30% alumina was investigated to study the effects of milling and sieving raw materials on bending strength and Weibull distribution of fired bodies. Test bars were formed by slip casting into a rectangular shape (10b×5b×70mm) and fired at 1350°C for 1h in a reducing atmosphere. Mean bending strength of the fired specimens increased with milling time, almost proportionally to time. Weibull modulus, however, decreased with milling time, because of a small amount of coarse grains which remained in the slip even after long milling. Removing the coarse grains in the slip through a finer sieve resulted in increased strength and higher Weibull modulus. It was found that quartz grains included in the raw feldspar were more effective as fracture sources than feldspar itself. A mean bending strength of 240MPa and Weibull modulus of 21 were obtained from the slip milled for 24h and sieved through 350mesh.
