Measurement of Bending Strength Using Specimens Cut from Commercially Produced High-Strength Porcelains

To estimate the strength of commercially produced porcelains, specimens must be cut from the commercial products. In this study, the effects of sample preparation processes, such as cutting or grinding, and measuring methods on the bending strength and its distribution were investigated for the specimens cut from commercial products, and compared with those of slip-cast specimens. The bending strength of specimens cut from traditional porcelains, which is smaller than 150MPa, agreed well with that of slip-cast specimens irrespective of sample preparation method. On the other hand, in the case of high-strength glazed porcelain products, which show values larger than 250MPa, the bending strength was estimated accurately by eliminating the chipping in glaze or cracks in the body by means of grinding away over 150μm on one side with a #400 diamond wheel, and agreed well with that of slip-cast specimens.