Surface treatment and strength of low-fired ceramic bodies: An experimental study

Abstract

This experimental investigation examines the influence of surface treatment on the strength of low-fired tempered ceramic bodies. Specimens prepared with commercial raw materials are employed, either finger-smoothed, burnished, textured, slipped/burnished, or resin coated; two building techniques, coiling and paddle-and-anvil, are also included since these forming processes affect the vessel surface. The modulus of rupture or flexural strength is determined by means of a four-point bending test, which is sensitive to critical surface flaws. By means of a univariate analysis of variance, small differences in strength are found between ceramic briquettes with different surface treatments. Although the differences in means for the moduli of rupture values are statistically significant, the differences are of such a low magnitude that they cannot be considered behaviorally relevant. These results are only valid for the materials, mode of preparation, and test procedures employed.