The Influence of Nanosized Leucite on Dental Porcelain Properties

2007 ◽  
Vol 280-283 ◽  
pp. 1605-1608 ◽  
Author(s):  
Jin Ping Yang ◽  
Jian Qing Wu ◽  
Ping Gen Rao ◽  
Chong Fei Xin ◽  
Dong Dan Chen
Keyword(s):  
Thermal Expansion ◽  
Flexural Strength ◽  
Thermal Expansion Coefficient ◽  
Expansion Coefficient ◽  
Sol Gel ◽  
Micro Structure ◽  
Dental Porcelain ◽  
Gel Method ◽  
Sol Gel Method

The influence of leucite on dental porcelain properties is investigated in this paper. The nanosized leucite powder prepared by sol-gel method was added into a low-fusing temperature frit to fabricate dental porcelain fused to metal. The porcelains with different leucite contents were sintered at the temperatures ranging from 780° to 900°C. The flexural strength and the thermal expansion coefficient (TEC) of the dental porcelain containing leucite particles are evaluated. The micro- structure and phases of the porcelain are characterized and the mechanism that nanosized leucite particles strengthening the porcelain is discussed.

scholarly journals Alternative of bone china and porcelain as ceramic hand molds for rubber latex glove films formation via dipping process

2020 ◽  
Vol 59 (1) ◽  
pp. 523-537
Author(s):  
Chaturaphat Tharasana ◽  
Aniruj Wongaunjai ◽  
Puwitoo Sornsanee ◽  
Vichasharn Jitprarop ◽  
Nuchnapa Tangboriboon
Keyword(s):  
Thermal Expansion ◽  
Flexural Strength ◽  
Thermal Expansion Coefficient ◽  
Expansion Coefficient ◽  
Mold Surface ◽  
Rubber Latex ◽  
Latex Glove ◽  
Bone China ◽  
Synthetic Rubber ◽  
Natural And Synthetic

AbstractIn general, the main compositions of porcelain and bone china composed of 54-65%wt silica (SiO2), 23-34% wt alumina (Al2O3) and 0.2-0.7%wt calcium oxide (CaO) suitable for preparation high quality ceramic products such as soft-hard porcelain products for teeth and bones, bioceramics, IC substrate and magneto-optoelectroceramics. The quality of ceramic hand mold is depended on raw material and its properties (pH, ionic strength, solid-liquid surface tension, particle size distribution, specific surface area, porosity, density, microstructure, weight ratio between solid and water, drying time, and firing temperatures). The suitable firing conditions for porcelain and bone china hand-mold preparation were firing at 1270°C for 10 h which resulted in superior working molds for making latex films from natural and synthetic rubber. The obtained fired porcelain hand molds at 1270°C for 10 h provided good chemical durability (10%NaOH, 5%HCl and 10%wtNaCl), low thermal expansion coefficient (5.8570 × 10−6 (°C−1)), good compressive (179.40 MPa) and good flexural strength (86 MPa). While thermal expansion coefficient, compressive and flexural strength of obtained fired bone china hand molds are equal to 6.9230 × 10−6 (°C−1), 128.40 and 73.70 MPa, respectively, good acid-base-salt resistance, a smooth mold surface, and easy hand mold fabrication. Both obtained porcelain and bone china hand molds are a low production cost, making them suitable for natural and synthetic rubber latex glove formation.

Crystallization Behavior and Performance of MgO-Al2O3-SiO2 Glass-Ceramics by Sintering

2010 ◽  
Vol 92 ◽  
pp. 65-71 ◽  
Author(s):  
Pei Xin Zhang ◽  
Li Gao ◽  
Qiu Hua Yuan ◽  
Hai Lin Peng ◽  
Xiang Zhong Ren ◽  
...  
Keyword(s):  
Thermal Expansion ◽  
Flexural Strength ◽  
Thermal Expansion Coefficient ◽  
Expansion Coefficient ◽  
Crystallization Process ◽  
Glass Ceramics ◽  
X Ray Diffraction ◽  
Low Thermal Expansion ◽  
Main Crystalline Phase ◽  
And Performance

The glass-ceramics of MgO-Al2O3-SiO2 system were prepared by sintering technology. The crystallization process of MgO-Al2O3-SiO2 glass-ceramics was investigated with X-ray diffraction (XRD), scanning electron microscopy (SEM), and other techniques; the discussion of breaking strength, thermal expansion coefficient and relevant properties at different sintering temperatures was also presented. The results show that: (1) The main crystalline phase isα-cordierite at different sintering temperatures, and the samples show high flexural strength and low thermal expansion coefficient; (2) with the increase of sintering temperature, the content of crystal phase increases, while the thermal expansion coefficient decreases evidently, the flexural strength and tightness density rise up first, then go down.

Synthesis of ZrW2O8 Ceramics and Composites from Aqueous Sol-Gel Precursors

2006 ◽  
Vol 45 ◽  
pp. 218-222
Author(s):  
Klaartje de Buysser ◽  
Serge Hoste ◽  
Isabel Van Driessche
Keyword(s):  
Phase Transition ◽  
Thermal Expansion ◽  
Thermal Expansion Coefficient ◽  
Expansion Coefficient ◽  
Sol Gel ◽  
Negative Thermal Expansion ◽  
Oxide Mixture ◽  
Stability Range ◽  
Cubic Symmetry ◽  
Geometrical Effect

The thermal expansion of a ceramic material in general leads to a positive thermal expansion coefficient (α). In the last decennium, several families of materials which exhibit negative thermal expansion, arising from a specific geometrical effect in their so-called open framework structures, have been discovered. Usually, this negative thermal expansion coefficient is small, anisotropic and the phenomena occur in a very small temperature interval. ZrW2O8 is an exception because of its large and isotropic negative thermal expansion coefficient (NTE) in a temperature range from 0.5K to 1050K. A cubic symmetry is found over the entire stability range with a phase transition from α-ZrW2O8 to β-ZrW2O8 near 430K. This phase transition is noticed by a change in α. The aqueous citrate-gel method is a suitable synthesis route for negative thermal expansion ceramics and will give a fine, pure and homogenous oxide mixture, well suitable for the preparation of ZrW2O8. The expansion coefficient of α–ZrW2O8 is -11 μm/m K whereas for the β- ZrW2O8 a value of -3 is obtained.

Effects of Heat-Treatment Temperature on the Properties of Negative CTE Eucryptite Ceramics

2010 ◽  
Vol 105-106 ◽  
pp. 123-125 ◽  
Author(s):  
Yong Li ◽  
Qi Hong Wei ◽  
Ling Li ◽  
Chong Hai Wang ◽  
Xiao Li Zhang ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Thermal Expansion ◽  
Thermal Expansion Coefficient ◽  
Expansion Coefficient ◽  
Heat Treatment Temperature ◽  
Bending Strength ◽  
Sol Gel ◽  
Negative Thermal Expansion ◽  
Treatment Temperature ◽  
Heat Treated

In this paper, negative thermal expansion coefficient eucryptite powders were prepared by sol-gel method using silica-sol as starting material. The raw blocks were obtained by dry pressing process after the powder was synthesized, and then the raw blocks were heat-treated at 600º, 1150º, 1280º, 1380º, 1420º and 1450°C, respectively. Variations of density, porosity and thermal expansion coefficient at different heat treatment temperatures were investigated. Phase transformation and fracture surface morphology of eucryptite heat-treated at different temperatures, respectively, were observed by XRD and SEM. The results indicate that, with the increasing heat- treatment temperature, the grain size and the bending strength increased, porosity decreased, thermal expansion coefficient decreased continuously. Negative thermal expansion coefficient of -5.3162×10-6~-7.4413×10-6 (0~800°C) was obtained. But when the heat-treatment temperature was more than 1420°C, porosity began to increase, bending strength began to decrease, which were the symbols of over-burning, while the main crystal phase didn’t change.

Microporous Alumino-Silicate Gels Synthesized by Sol-Gel Method

1994 ◽  
Vol 346 ◽  
Author(s):  
L. Chu ◽  
G. Yaluris ◽  
W. A. Zeltner ◽  
M. A. Anderson
Keyword(s):  
Negative Charge ◽  
Sol Gel ◽  
Nitrate Solution ◽  
Micro Structure ◽  
Gel Method ◽  
Sol Gel Method ◽  
Water Based ◽  
Alumino Silicate ◽  
Ph Conditions ◽  
Silica Sols

ABSTRACTMicroporous alumino-silicate gels were prepared by the sol-gel method. The Al cations were incorporated into these systems by mixing an aluminum nitrate solution into silica water based sols under controlled pH conditions. The micro structure as well as the form of the products are influenced by the amount of Al additives. Al cations have significant effects on the properties of silica sols and gels. The alumino-silicate gel has micro porosity with surface area as high as 300 m2/g even after calcining at 900 °C for one hour. Strong negative charge is found on these alumino-silicate surfaces in aqueous solution indicating the Al cations have been substituted isomorphically into the Si sites in the framework of silica.

Nanosize Beta-Spodumene Glass-Ceramic Powders Synthesized by Sol–Gel Route

2011 ◽  
Vol 110-116 ◽  
pp. 3844-3848
Author(s):  
Zhuo Hao Xiao ◽  
Wen Yan Luo
Keyword(s):  
Thermal Expansion ◽  
Electron Microscope ◽  
Thermal Expansion Coefficient ◽  
Expansion Coefficient ◽  
Glass Ceramic ◽  
Sol Gel ◽  
Ceramic Powder ◽  
Average Particle Size ◽  
Glass Ceramics ◽  
Average Particle

Beta-spodumene glass-ceramic powder was prepared by Sol–gel route. Tetraethyl orthosilicate (TOES), aluminum nitrate, lithium carbonate were used as starting materials. X-ray powder diffraction (XRD), thermal expansion coefficient (TEC), scanning electron microscope (SEM) and transmission electron microscope (TEM) were utilized to characterize the dried LAS gels and glass-ceramic blocks. The results suggest beta-spodumene is the only crystals phase in the prepared LAS glass-ceramics powder when sintering temperature is 950 °C. The average particle size of the beta-spodumene crystal is about 30 nm with a narrow size distribution both in prepared LAS glass-ceramics powder and block. The thermal expansion coefficient of moulding pressed blocky LAS glass-ceramics is lower than 0.6×10-6 oC-1.

Fabrication of negative thermal expansion ZrMo2O8 film by sol–gel method

2012 ◽  
Vol 177 (2) ◽  
pp. 263-268 ◽  
Author(s):  
Qinqin Liu ◽  
Xiaonong Cheng ◽  
Juan Yang ◽  
Xiujuan Sun
Keyword(s):  
Thermal Expansion ◽  
Sol Gel ◽  
Negative Thermal Expansion ◽  
Gel Method ◽  
Sol Gel Method

Thermal Expansion Property of P2O5 Doped Lithium Aluminosilicate Glass-Ceramic Synthesized by Sol-Gel Process

2010 ◽  
Vol 663-665 ◽  
pp. 1281-1284
Author(s):  
Zhuo Hao Xiao ◽  
Wen Yan Luo ◽  
Sheng Long Wang
Keyword(s):  
Thermal Expansion ◽  
Thermal Expansion Coefficient ◽  
Expansion Coefficient ◽  
Glass Ceramic ◽  
Sol Gel ◽  
Glass Ceramics ◽  
Lithium Carbonate ◽  
Aluminosilicate Glass ◽  
Lithium Aluminosilicate ◽  
Thermal Expansion Property

Lithium aluminosilicate (LAS) glass-ceramics with 0 ~ 10 wt% phosphoric anhydride were prepared by sol-gel method and sintering at high temperature. Tetraethyl orthosilicate (TOES), aluminum nitrate, lithium carbonate were used as precursors. Differential thermal analysis (DTA), X-ray powder diffraction (XRD) and thermal expansion coefficient (TEC) were used to characterize the dried LAS gels and glass-ceramic blocks. The results suggest β-spodumene solid-solution is the only crystals phase in the P2O5 doped LAS glass-ceramics when sintering temperature is 950 oC. The thermal expansion coefficient of the P2O5 doped LAS glass-ceramics range from -0.1×10-6 oC-1 to 1.2×10-6 oC-1. Compared with the conventional melt quenching method, this process route provides a low temperature and timesaving method for preparing LAS glass-ceramics.

scholarly journals Synthesis of Al2O3-SiO2 Glasses from Sol-Gel Method and Their Thermal Expansion

1989 ◽  
Vol 97 (1123) ◽  
pp. 224-228 ◽  
Author(s):  
Tosio TSUCHIYA ◽  
Masanao FUKUOKA ◽  
Tadanori SEI ◽  
J. D. MACKENZIE
Keyword(s):  
Thermal Expansion ◽  
Sol Gel ◽  
Gel Method ◽  
Sol Gel Method

Effect of the Cooling Ways on the Properties and Microstructure of ZrO2/ZrW2O8 Ceramic Composites

2016 ◽  
Vol 697 ◽  
pp. 381-385 ◽  
Author(s):  
Jin Ping Li ◽  
Cheng Yang ◽  
Song He Meng ◽  
Fa Jun Yi ◽  
Yu Han Li
Keyword(s):  
Thermal Expansion ◽  
Flexural Strength ◽  
Thermal Expansion Coefficient ◽  
Expansion Coefficient ◽  
Chemical Properties ◽  
Ceramic Composites ◽  
Cold Isostatic Pressing ◽  
Thermal Expansion Coefficients ◽  
Lower Thermal Expansion ◽  
Physical And Chemical

ZrO2 has been widely used due to its good physical and chemical properties and the ZrO2/ZrW2O8 ceramic composites with adjustable thermal expansion coefficient can be prepared by mixing and sintering the ZrO2 and ZrW2O8 powders. In this paper, the ZrO2/ZrW2O8 ceramic composites have been prepared by mixing, cold isostatic pressing and atmospheric sintering, and then being cooled in air or in water. We focus on the effect of the cooling ways on the properties and microstructure of the ZrO2/ZrW2O8 ceramic composites. The results show that the relative density of all samples is more than 98%. For the in-situ method, the density and flexural strength of the samples cooled in air and in water are 98.1% and 98.4%, 112.96MPa and 45.23MPa, respectively. The ZrW2O8 content and thermal expansion coefficient of the samples cooled in the air are less and higher than those in the water, respectively. For the direct mixture method, the density and flexural strength of the samples cooled in air and in water are 98.9% and 99.3%, 195.99MPa and 58.71MPa, respectively. For the four groups of the composite samples, they behave better mechanical properties after cooled in air, and lower thermal expansion coefficients after cooled in water.

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