The influence of microstructure on the performance of white porcelain stoneware

In the last years polished white porcelain stoneware tiles, coupling the smooth and glossy surface with the increased body whiteness, get a prominent role on the market. The bright white colour is obtained by adding noteworthy quantity of opacifiers, such as zircon, corundum and spinel. To better understand the complex relationships among the microstructure and the mechanical, tribological and functional behaviour of this class of products, four polished white porcelain stoneware tiles were selected and thoroughly characterized by a wide spectrum of chemico-physical and microstructural analyses. Products exhibit excellent mechanical properties (flexural strength, Young modulus, fracture toughness) with a clear dependence of these properties on porosity and phase composition. Mullite and zircon tend to increase the mechanical performances, through a predominant mechanism of matrix reinforcement, while quartz plays an opposite role.