Abstract
Sintering of phosphate-added MgO and the reaction between phosphates and magnesia were studied by means of thermal dilatometry and high-temperature X-ray diffraction analysis.
Some magnesium pyrophosphate-added MgO compacts, exanding temporaily on the formation of Mg3 (PO4) 2 from MgO and Mg2P2O7, shrank to a great extent compared with those containing other phosphates. The shrinkage rates of phosphate-added magnesia compacts began to increase at about 1000°C, while MgO compacts containing no phosphate shrank rapidly above 1100°C. The formation or the presence of Mg3 (PO4) 2 accelerated shrinkage and sintering of MgO compacts.
