Reaction and phases from monoclinic zirconia and calcium aluminate cement at high temperatures

Solid state reaction using m-ZrO2 and high alumina cement as starting materials was studied. Various compositions containing different proportions of calcium aluminate cement (5–50 mol% CaO in ZrO2) were reaction sintered at 1300–1500 °C. Crystalline phase formation and densification of Ca stabilized ZrO2 composites was investigated by X-ray diffraction analysis, density and shrinkage measurements. Scanning electron microscopy (SEM) combined with energy dispersive X-ray spectroscopy was used to examine the microstructure. The main crystalline phases formed are related to the expected with the equilibrium phase diagram of the ZrO2–CaO–Al2O3 system. Stabilized c-ZrO2 is formed with the composition of Ca0.15Zr0.85O1.85. The sintering of the mixtures leads to porous composites materials. Textural properties were analyzed considering the initial composition and the present crystalline phases.