Effect of Al2O3 Addition on the Flexural Strength and Light-Transmission Properties of Bone China

To improve the flexural strength and light-transmission properties of bone china, the effects of adding different amounts of alumina (0-3%) to bone china bodies were studied and the phase composition and microstructure of different samples were studied by X-ray diffraction (XRD) and scanning electron microscopy (SEM). In addition, physical properties, such as the bulk density, the thermal expansion coefficient (TEC) and thermal shock resistance, were studied. It was found that adding alumina increased the overall sintering temperature while reducing the sintering temperature range of bone china. Furthermore, addition of 1% Al2O3 improved the tree-point flexural strength from 120 MPa to 150 MPa, the light transmittance (at 2mm thickness) from 6.7% to 7.5%, the thermal expansion coefficient from 8.4x10(-6)degrees C-1 to 8.1x10(-6)degrees C-1 and the thermal shock resistance from 140 degrees C to 180 degrees C. Higher corundum content results in similar high flexural strength but lower light transmittance.