Nanocrystalline Seeding Effect on the Crystallization of Two Leucite Precursors

Abstract

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.

Effects of multiple firings on the mechanical properties and microstructure of veneering ceramics for zirconia frameworks

“…19,33 The possible mechanisms of this change are crystallization on the one hand or dissolution on the other. 34 Cristobalite precipitation in the composite takes place during firing, but it can be prevented by the presence of Al ions. 35 The size and number of the fluorapatite crystals were influenced by ripening and dissolving effects, and the X-ray intensity of the apatite phase depended on the heat treatment temperature.…”

Mechanical Properties of Dental Porcelain with Different Leucite Particle Sizes

“…The LTF selected for this study was prepared according to the method described elsewhere 22,23 . The frit had the following composition (wt%): 59% SiO 2 , 13% Al 2 O 3 , 9% K 2 O, 10% Na 2 O, 2% CaO, 2% CeO, 1.5% Li 2 O, 1% CaF 2 , 1% MgO, 1% BaO, and 0.5% ZrO 2 .…”

“…The study of leucite particle size effect on the mechanical properties of dental porcelain may be instructive for the production of dental porcelain to achieve optimum mechanical properties with a lower cost. Moreover, the authors have prepared leucite powders with different particle sizes in their previous research 21,22 . In the present study, synthetic leucite particles with different particle size distributions were introduced into a low‐temperature frit (LTF) to fabricate dental porcelains with a different microstructure.…”

Enhanced oxidation resistance of hydrothermally-encapsulated CdS nanoparticles in SiO2-CeO2 matrices

“…18) Then, 1/3 amount of the former-prepared CdS-CeO2 nanoparticles were added to the prehydrolyzed TEOS with ultrasonication for 30min, while controlling the pH value between 2-3. The mixture was stirred to gel at 60°C and further dried at 60°C and 100°C for 24 h and 6 h, respectively.…”