A view of whitewares mechanical strength and microstructure

A traditional porcelain composed of kaolin, quartz and feldspar was formed by pressing and was sintered at temperature between 1200 °C and 1420 °C. The samples were characterized before and after sintering. A KIC of 1.6 MPa m1/2 was found for a sample fired at 1340 °C. X-ray diffraction showed the presence of mullite, quartz and glassy phase. The microstructures of samples sintered at different temperatures were analyzed by Scanning Electron Microscopy (SEM). The SEM analysis revealed that the ideal firing temperature was a consequence of glassy phase characteristics and that the maximum MOR was limited by a flaw made by quartz stress releasing. SEM images of this flaw, pore and flaw linking are showed.