PREPARATION OF DISPERSED ZIRCONIA BARIUM ALUMINOSILICATE COMPOSITES

The potential for preparing a ZrO2-containing ceramic composite based on barium feldspar (BaAl2Si2O8) using the reaction sintering of zircon has been investigated It is demonstrated that, through the reaction o f ZrSiO4, Al2O3 and BaCO3 above 1400 degrees C, a distribution of ZrO2 particles in a BaO . Al2O3 . 2SiO(2) matrix can be achieved. A glassy phase rich in Si and Ba surrounds the zirconia particles and infiltra tes the grain boundaries of the polycrystalline feldspar matrix. The t endency of the ZrO2 particles to agglomerate within the matrix can be reduced by incorporating additional silica into the reaction, while li mited stabilisation of tetragonal ZrO2 can be achieved by additions of Y2O3 which partition between the ZrO2 and the glassy boundary phase.