Relationship between microstructure and mechanical properties in fully vitrified stoneware

Fully vitrified stoneware tiles are very important low-porosity products obtained by high-sintering of unglazed ceramic bodies and used for exterior applications and as frost-resistant materials. The dense microstructure of thp fired tiles is characterized by strongly interlocked crystals of quartz and mullite embedded in an amorphous glassy phase. Vickers microhardness (4.94-6.09 GPa), Young's modulus (68.7-73.6 GPa) and abrasion resistance (1.48-1.84 g/30x30 tile) of industrial fully vitrified stoneware tiles were measured and well represent the mechanical properties of the tiles. The microstructure is responsible for the peculiar abrasion resistance and hardness, and correlations among these mechanical properties and microstructure are discussed.