Nanocrystalline Seeding Effect on the Crystallization of Two Leucite Precursors

The effect of nanocrystalline leucite seeding with leucite precursors prepared by sol–gel and hydrothermal methods on the leucite crystallization process and the microstructure of its sintered porcelain was studied. The introduced seeds lowered the crystallization temperature of leucite by 100° and 50°C for the precursor prepared by hydrothermal and sol–gel methods, respectively. The crystallization process was changed after the seeds were introduced. As the transition phase during leucite crystallization, kalsilite did not appear after the seeds were added. When the seeded hydrothermally derived precursor was treated at 650° and 700°C, part of the cubic leucite was stabilized to room temperature. This stabilization was due to the crystallization of nanocrystalline leucite on the seeds at a low temperature. The leucite synthesized by the hydrothermal method with seeding at 800°C had an average particle size of 0.4 μm that grew to about 0.6 μm in the sintered porcelain.