Thermal expansion of ceramic samples containing natural zeolite

2017 ◽  
Author(s):  
Ivana Sunitrová ◽  
Anton Trník
Keyword(s):  
Thermal Expansion ◽  
Natural Zeolite ◽  
Ceramic Samples

scholarly journals Thermophysical Properties of Kaolin–Zeolite Blends up to 1100 °C

Crystals ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 165
Author(s):  
Ján Ondruška ◽  
Tomáš Húlan ◽  
Ivana Sunitrová ◽  
Štefan Csáki ◽  
Grzegorz Łagód ◽  
...  
Keyword(s):  
Thermal Expansion ◽  
Thermal Diffusivity ◽  
Thermophysical Properties ◽  
Natural Zeolite ◽  
Laser Flash ◽  
Optimal Amount ◽  
Ceramic Samples ◽  
Zeolite Content ◽  
Negative Effect ◽  
Cylindrical Samples

In this study, the thermophysical properties such as the thermal expansion, thermal diffusivity and conductivity, and specific heat capacity of ceramic samples made from kaolin and natural zeolite are investigated up to 1100 °C. The samples were prepared from Sedlec kaolin (Czech Republic) and natural zeolite (Nižný Hrabovec, Slovakia). Kaolin was partially replaced with a natural zeolite in the amounts of 10, 20, 30, 40, and 50 mass%. The measurements were performed on cylindrical samples using thermogravimetric analysis, a horizontal pushrod dilatometer, and laser flash apparatus. The results show that zeolite in the samples decreases the values of all studied properties (except thermal expansion), which is positive for bulk density, porosity, thermal diffusivity, and conductivity. It has a negative effect for thermal expansion because shrinkage increases with the zeolite content. Therefore, the optimal amount of zeolite in the sample (according to the studied properties) is 30 mass%.

scholarly journals Augite-anorthite glass-ceramics from residues of basalt quarry and ceramic wastes

2015 ◽  
Vol 9 (2) ◽  
pp. 117-123 ◽  
Author(s):  
Gamal Khater ◽  
Safiah Abu ◽  
Esmat Hamzawy
Keyword(s):  
Thermal Expansion ◽  
Glass Ceramic ◽  
Crystallization Process ◽  
Coefficient Of Thermal Expansion ◽  
Glass Ceramics ◽  
Ceramic Samples ◽  
Heat Treated ◽  
Prepared Glass ◽  
Higher Temperature ◽  
Dominant Phase

Dark brown glasses were prepared from residues of basalt quarries and wastes of ceramic factories. Addition of CaF2, Cr2O3 and their mixture CaF2-Cr2O3 were used as nucleation catalysts. Generally, structures with augite and anorthite as major phases and small amount of magnetite and olivine phases were developed through the crystallization process. In the samples heat treated at 900?C the dominant phase is augite, whereas the content of anorthite usually overcomes the augite at higher temperature (1100?C). Fine to medium homogenous microstructures were detected in the prepared glass-ceramic samples. The coefficient of thermal expansion and microhardnessmeasurements of the glass-ceramic samples were from 6.16?10-6 to 8.96?10-6?C-1 (in the 20-500?C) and 5.58 to 7.16GP, respectively.

scholarly journals Uncertainty Of The Measurement Of DC Conductivity Of Eramics At Elevated Temperatures

2015 ◽  
Vol 66 (1) ◽  
pp. 34-39 ◽  
Author(s):  
Igor Štubňa ◽  
Viera Trnovcová ◽  
Libor Vozár ◽  
Štefan Csáki
Keyword(s):  
Thermal Expansion ◽  
Temperature Field ◽  
Field Measurement ◽  
Elevated Temperatures ◽  
Conductivity Measurement ◽  
Dc Conductivity ◽  
Expanded Uncertainty ◽  
Ceramic Samples ◽  
Temperature Dependences ◽  
Sample Homogeneity

Abstract The electrical DC conductivity is measured at room and elevated temperatures on green ceramic samples prepared from kaolin. The arrangement of the sample, with two platinum wire electrodes inserted in the kaolin prism that was used is suitable for measurements of temperature dependences of the DC conductivity from 20 °C to 1100 °C in the air. The uncertainty analysis taking into account thermal expansion of the sample, homogeneity of the temperature field, measurement regime, corrosion of the electrodes, and overlapping of the electrodes is done for 1000 °C. Uncertainties connected with current and voltage measurements and uncertainties connected with the instruments that were used are also considered. The sum of all the partial uncertainties gives an expanded uncertainty of the conductivity measurement. The uncertainty varies with temperature and reaches the value of ∼ 6.5% at 1000 °C.

scholarly journals Ceramic bricks with enhanced thermal insulation produced from natural zeolite

2021 ◽  
Author(s):  
Jamal Eldin F. M. Ibrahim ◽  
Emese Kurovics ◽  
Mohammed Tihtih ◽  
László A. Gömze
Keyword(s):  
Thermal Insulation ◽  
Natural Zeolite ◽  
Sintering Temperature ◽  
Research Work ◽  
X Ray Diffraction ◽  
X Ray ◽  
Ceramic Samples ◽  
Dry Pressing ◽  
Microstructure Morphology ◽  
Potential Use

AbstractIn this research, ceramic bricks were produced based on natural zeolite from Tokaj (Hungary) using the dry pressing technique. The microstructure, morphology and properties of the produced samples were examined via scanning electron microscopy, X-ray diffraction and X-ray fluorescence. The X-ray investigation revealed various minerals in the natural zeolite; moreover, the samples’ physical and thermal properties were also investigated. The sintering temperature and composition play a major role in the microstructure and the properties of the prepared ceramic samples. The produced ceramics bricks have excellent thermal insulation and good mechanical strength. The results of this research work confirm the potential use of natural zeolite from Tokaj as an eco-friendly building material.

scholarly journals Measuring the Flexural Strength of Ceramics at Elevated Temperatures – An Uncertainty Analysis

2014 ◽  
Vol 14 (1) ◽  
pp. 35-40 ◽  
Author(s):  
I. Štubňa ◽  
P. Šín ◽  
A. Trník ◽  
L. Vozár
Keyword(s):  
Thermal Expansion ◽  
Flexural Strength ◽  
Uncertainty Analysis ◽  
Mechanical Strength ◽  
Elevated Temperatures ◽  
Standard Uncertainty ◽  
Three Point Bending ◽  
Mechanical Parts ◽  
Ceramic Samples ◽  
Mechanical Arrangement

Abstract The flexural mechanical strength was measured at room and elevated temperatures on green ceramic samples made from quartz electroporcelain mixture. An apparatus exploited the three-point-bending mechanical arrangement and a magazine for 10 samples that are favorable at the temperature measurements from 20 °C to 1000 °C. A description of the apparatus from the point of possible sources of uncertainties is also given. The uncertainty analysis taking into account thermal expansion of the sample and span between the supports is performed for 600 °C. Friction between the sample and supports as well as friction between mechanical parts of the apparatus is also considered. The value of the mechanical strength at the temperature of 600 °C is 13.23 ± 0.50 MPa, where the second term is an expanded standard uncertainty. Such an uncertainty is mostly caused by inhomogeneities in measured samples. The biggest part of the uncertainty arises from the repeatability of the loading force which reflects a scatter of the sample properties. The influence of the temperature on the uncertainty value is very small

Microstructural and Microchemical Characterization of Nickel Sulfide Inclusions in Plate Glass

1991 ◽  
Vol 49 ◽  
pp. 962-963
Author(s):  
J. Cooper ◽  
O. Popoola ◽  
W. M. Kriven
Keyword(s):  
Thermal Expansion ◽  
Phase Transformation ◽  
Glass Matrix ◽  
Nickel Sulfide ◽  
Plate Glass ◽  
Thermal Expansion Mismatch ◽  
Volume Increase ◽  
Β Phase ◽  
Microchemical Characterization

Nickel sulfide inclusions have been implicated in the spontaneous fracture of large windows of tempered plate glass. Two alternative explanations for the fracture-initiating behaviour of these inclusions have been proposed: (1) the volume increase which accompanies the α to β phase transformation in stoichiometric NiS, and (2) the thermal expansion mismatch between the nickel sulfide phases and the glass matrix. The microstructure and microchemistry of the small inclusions (80 to 250 μm spheres), needed to determine the cause of fracture, have not been well characterized hitherto. The aim of this communication is to report a detailed TEM and EDS study of the inclusions.

Transmission Electron Microscopy study of Bi-based superconducting phases

1990 ◽  
Vol 48 (4) ◽  
pp. 50-51
Author(s):  
J.G. Wen ◽  
K.K. Fung
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Single Crystals ◽  
Microscopy Study ◽  
Electron Microscopy Study ◽  
Space Groups ◽  
Superconducting Phases ◽  
Ceramic Samples ◽  
Transmission Electron ◽  
Modulated Structures

Bi-based superconducting phases have been found to be members of a structural series represented by Bi2Sr2Can−1Cun−1On+4, n=1,2,3, and are referred to as 2201, 2212, 2223 phases. All these phases are incommensurate modulated structures. The super space groups are P2/b, NBbmb 2201, 2212 phases respectively. Pb-doped ceramic samples and single crystals and Y-doped single crystals have been studied by transmission electron microscopy.Modulated structures of all Bi-based superconducting phases are in b-c plane, therefore, it is the best way to determine modulated structure and c parameter in diffraction pattern. FIG. 1,2,3 show diffraction patterns of three kinds of modulations in Pb-doped ceramic samples. Energy dispersive X-ray analysis (EDAX) confirms the presence of Pb in the three modulated structures. Parameters c are 3 0.06, 38.29, 30.24Å, ie 2212, 2223, 2212 phases for FIG. 1,2,3 respectively. Their average space groups are all Bbmb.

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