Phase Composition, Mechanical and Thermal Properties of (MgO)0.1-x(YO1.5)x(ZrO2)0.9 and (MgO)0.1-x(CaO)x(ZrO2)0.9 Ceramics

2008 ◽  
Vol 368-372 ◽  
pp. 751-753
Author(s):  
Chuan Gang Fan ◽  
Lan Xu ◽  
Jie Rong Yan ◽  
Cui Hong Zheng ◽  
Jia Mao Li
Keyword(s):  
Thermal Properties ◽  
Phase Composition ◽  
Flexural Strength ◽  
Bulk Density ◽  
Thermal Shock ◽  
Thermal Shock Resistance ◽  
Abrupt Change ◽  
Mechanical And Thermal Properties ◽  
Shock Resistance

(MgO)0.1-x(YO1.5)x(ZrO2)0.9 (MYZ) and (MgO)0.1-x(CaO)x(ZrO2)0.9 (MCZ) ceramics were prepared and their phase composition, bulk density, flexural strength, and thermal shock resistance were characterized. There was an abrupt change of c/(c+m) from 29% to 75% as 0<x<0.01 for MYZ, and a change of c/(c+m) from 42% to 88% appeared as 0.02<x<0.03 for MCZ (the c and m representing the content of the cubic and the monoclinic phases respectively). When x=0.01~0.05, the resulting MYZ specimens had the resembling c/(c+m) at about 75%, and a thermal shock resistance of more than 5 times (1100oC⇔25oC) appeared for x=0.03~0.05 specimens. However for MCZ, only specimen of x=0.01 with c/(c+m) of 33% had a thermal shock resistance more than 5 times.

Effect of Pyrophyllite on the Mullite Generation in Ternary Porcelain System

2012 ◽  
Vol 512-515 ◽  
pp. 575-579
Author(s):  
J.H. Pee ◽  
A.N. Kwak ◽  
Jong Young Kim ◽  
Yoo Jin Kim ◽  
Kyung Ja Kim
Keyword(s):  
Thermal Expansion ◽  
Thermal Properties ◽  
Water Absorption ◽  
Bulk Density ◽  
Thermal Shock ◽  
Thermal Expansion Coefficient ◽  
Expansion Coefficient ◽  
Thermal Shock Resistance ◽  
Mechanical And Thermal Properties ◽  
Shock Resistance

Promoting of mullite generation has been studied by replacing kaolinite with pyrophyllite because of mullite has excellent strength and thermal shock resistance. Effects of promoting of mullite generation and vitrification by replacing kaolinite with pyrophyllite on the mechanical and thermal properties were investigated. Addition of 45-55% pyrophyllite as a replacement of kaolinite (pyrophyllite (45-55%)-feldspar (30%)-clay (20%)) could vitrify samples (water absorption: 0.05%, bulk density: 2.66g/cm3) and improve the strength (122MPa) of samples fired at 1280°C. In ternary porcelain system, pyrophyllite-feldspar-clay, mullite generation of samples with 50% pyrophyllite reaches about 78.7% and thermal expansion coefficient is 5.4×10-6/K. Beyond 50% pyrophyllite addition, quartz and cristobalite phases increased. And thermal expansion coefficient of samples decreased with increasing of mullite amount.

The Effect of Phase Composition on the Mechanical and Thermal Properties of LTCC Material

2012 ◽  
Vol 2012 (CICMT) ◽  
pp. 000492-000497
Author(s):  
Kostja Makarovič ◽  
Anton Meden ◽  
Marko Hrovat ◽  
Janez Holc ◽  
Andreja Benčan ◽  
...  
Keyword(s):  
Thermal Properties ◽  
Phase Composition ◽  
Flexural Strength ◽  
Mass Fraction ◽  
Major Change ◽  
Multilayer Structures ◽  
Propagation Mechanism ◽  
Mechanical And Thermal Properties ◽  
Thermal Coefficient ◽  
Biaxial Flexural Strength

Low-temperature co-fired ceramic (LTCC) is an important material in the production of ceramic multilayer structures. Large and complex multilayer structures are usually fired at higher temperatures and/or longer firing times compared to the relatively thin LTCC tapes. The firing conditions of LTCC determine the phase composition and the microstructure, which both influence the physical characteristics, such as the mechanical and thermal properties. In this work the effect of the phase composition on the biaxial flexural strength and the temperature coefficient of expansion of the DuPont 951 LTCC is presented. The samples were fired at different temperatures and times to obtain different phase compositions. The phase composition, especially the mass fraction of anorthite, was correlated with the biaxial flexural strength and the thermal coefficient of expansion (TCE). A very long firing time, i.e., 100h at 800 °C, yields, apart from crystalline anorthite, the cristobalite phase. The anorthite that crystalizes from the glass phase in a dense LTCC material changes the crack-propagation mechanism and improves the biaxial flexural strength of the material. The major change in the biaxial flexural strength is observed when the anorthite phase appeared. The increasing mass fraction of anorthite does improve the biaxial flexural strength less drastically. With the increasing mass fraction of the anorthite, decreases of the TCE of the material and a small decrease of the density of the LTCC material occur.

Viability of Some Kano-Nigerian Clays for Refractory Applications

2013 ◽  
Vol 315 ◽  
pp. 477-481 ◽  
Author(s):  
I.A. Rafukka ◽  
B. Onyekpe ◽  
Y. Tijjani
Keyword(s):  
Compressive Strength ◽  
Physical Properties ◽  
Bulk Density ◽  
Thermal Shock ◽  
Thermal Shock Resistance ◽  
Linear Shrinkage ◽  
Chemical Compositions ◽  
Shock Resistance ◽  
Materials Used ◽  
Refractory Bricks

The physical properties of some materials used by local foundries were investigated with a view to assessing their suitability for use as low heat duty refractory bricks. The samples were collected from Malamai village, Gezawa Local Government, Kano state; they are Gezawa clay and Burji (Clay). The samples were crushed, ground, sieved and the chemical compositions were determined. The clay samples were treated separately as well as blended with Gezawa clay in different proportions and molded in to bricks. The bricks were dried and fired to 1100. Test for refractoriness, thermal shock resistance, linear shrinkage; bulk density, porosity and compressive strength were carried out on each of the specimen. Burji blended with 50% to 90% Gezawa clay gave improved thermal shock resistance with a refractoriness of 1300 and hence could be used for non ferrous melting cupolas.

Thermal Properties and Thermal Shock Resistance of γ-Y2Si2O7

2008 ◽  
Vol 91 (8) ◽  
pp. 2623-2629 ◽  
Author(s):  
Ziqi Sun ◽  
Yanchun Zhou ◽  
Jingyang Wang ◽  
Meishuan Li
Keyword(s):  
Thermal Properties ◽  
Thermal Shock ◽  
Thermal Shock Resistance ◽  
Shock Resistance

scholarly journals Physical, mechanical and thermal properties of Crushed Sand Concrete containing Rubber Waste

2018 ◽  
Vol 149 ◽  
pp. 01076
Author(s):  
Guendouz Mohamed ◽  
Boukhelkhal Djamila
Keyword(s):  
Thermal Conductivity ◽  
Thermal Properties ◽  
Flexural Strength ◽  
Municipal Solid Waste ◽  
Solid Waste ◽  
Bulk Density ◽  
Mechanical And Thermal Properties ◽  
The Past ◽  
Rubber Waste ◽  
And Performance

Over the past twenty years, the rubber wastes are an important part of municipal solid waste. This work focuses on the recycling of rubber waste, specifically rubber waste of used shoes discharged into the nature and added in the mass of crushed sand concrete with percentage (10%, 20%, 30% and 40%). The physical (workability, fresh density), mechanical (compressive and flexural strength) and thermal (thermal conductivity) of different crushed sand concrete made are analyzed and compared to the respective controls. The use of rubber waste in crushed sand concrete contributes to reduce the bulk density and performance of sand concrete. Nevertheless, the use of rubber aggregate leads to a significant reduction in thermal conductivity, which improves the thermal insulation of crushed sand concrete.

Effect of AlF3 Content on Microstructure and Properties of Mullite/Al2O3 Composite Ceramics

2018 ◽  
Vol 922 ◽  
pp. 62-67
Author(s):  
Ke Zheng Sang ◽  
Fan Wang ◽  
De Jun Zeng ◽  
Hong Wei Li
Keyword(s):  
Fracture Toughness ◽  
Flexural Strength ◽  
Thermal Shock ◽  
Thermal Shock Resistance ◽  
Diameter Ratio ◽  
Pressureless Sintering ◽  
Composite Ceramics ◽  
Microstructure And Properties ◽  
Shock Resistance ◽  
Mullite Whiskers

To reinforce the mullite/Al2O3 composite ceramics through formation of mullite whiskers, the composite ceramics were prepared by pressureless sintering using different AlF3 content. The microstructure, porosity, fracture toughness and thermal shock resistance of the composite ceramics were investigated. The results show that the addition of AlF3 can promote the mullite whisker formations, and the whiskers with the size of 3～10μm in diameter and a length-diameter ratio of 10～15 are obtained by sintering at 1600°C with the AlF3 content of 5wt%. Fracture toughness and thermal shock resistance of the composite ceramics are improved by the formation of mullite whisker. The fracture toughness of 4.79MPa•m1/2 can be obtained, and the 95.18% flexural strength remained after thermal shock.

Effect of MgO/CuO on the Microstructure and Thermal Properties of Cordierite–Alumina Ceramics

2012 ◽  
Vol 509 ◽  
pp. 240-244
Author(s):  
Li Ying Tang ◽  
Xi Cheng ◽  
Ping Lu ◽  
Fang Yue
Keyword(s):  
Thermal Conductivity ◽  
Bulk Density ◽  
Thermal Shock ◽  
Thermal Shock Resistance ◽  
Raw Materials ◽  
Laser Flash ◽  
Alumina Powder ◽  
Alumina Ceramics ◽  
Conductivity Increase ◽  
Shock Resistance

Abstract: Cordierite–alumina ceramics were prepared with the raw materials of cordierite and α-alumina powder, and TiO2，CuO and MgO were added as composite additives. The effect of MgO/ CuO ratios on the microstructure, thermal conductivity and thermal shock resistance of cordierite–alumina ceramics were researched by X-ray diffraction, scanning electron microscopy and laser flash analyzer; the bulk density and the porosity of cordierite – alumina ceramics were measured. The results show that with increasing of MgO/CuO ratios, the bulk density and thermal conductivity increase firstly and then decrease, and have a minimum with 0.4wt% MgO and 0.667 MgO/CuO; and the porosity of ceramics decreases firstly and then increases and has a maximum with 0.4wt% MgO and 0.667 MgO/CuO;There are little changes in the size of the grain of the ceramics, and a small amount of magnesium aluminate spinel precipitate; the thermal shock resistance performance of the ceramics is developed with the increasing of MgO/CuO ratios.

The Effects of Constraint, Size and Aspect Ratio on Thermal Shock Resistance of ZNS Wave-Transparent Ceramic in its Actual Service

2015 ◽  
Vol 31 (4) ◽  
pp. 449-455 ◽  
Author(s):  
W.-G. Li ◽  
D.-J. Li ◽  
T.-B. Cheng ◽  
D.-N. Fang
Keyword(s):  
Theoretical Model ◽  
Aspect Ratio ◽  
Thermal Shock ◽  
Thermal Shock Resistance ◽  
Transparent Ceramic ◽  
Aerodynamic Heating ◽  
Mechanical And Thermal Properties ◽  
Pneumatic Pressure ◽  
Actual Service ◽  
Shock Resistance

AbstractThe thermal shock resistance (TSR) of ZnS wave-transparent ceramic depends on not only the mechanical and thermal properties of materials, but also the aerodynamic heating, pneumatic pressure, external constraint, size, aspect ratio and other factors in its actual service process. The theoretical model was established by introducing the analytical solution of transient heat conduction problem of ZnS plate under aerodynamic heating into its thermal stress field model and the pneumatic pressure was introduced. The present work mainly focused on the influences of constraint, size and aspect ratio on the critical rupture temperature difference of ZnS plate subjected to aerodynamic heating and pneumatic pressure. The numerical simulation was also conducted to verify the theoretical model. The results show that the large heat transfer condition corresponds to the poor TSR unless the constraint is too strong; the square plate provides the better TSR in case of different pneumatic pressures; a reasonable side length according to the range of pneumatic pressure would lead to the better TSR.

Preparation and Performance of β-Sialon Bonded ZrO2 Composites

2011 ◽  
Vol 415-417 ◽  
pp. 138-141
Author(s):  
Rui Sheng Wang ◽  
Jun Hong Zhao ◽  
Ying Na Wei ◽  
Fu Hua Peng ◽  
Heng Yong Wei
Keyword(s):  
Thermal Expansion ◽  
Flexural Strength ◽  
Thermal Shock ◽  
Thermal Shock Resistance ◽  
Reaction Sintering ◽  
Sintering Process ◽  
Carbon Addition ◽  
Shock Resistance ◽  
And Performance ◽  
Sialon Powder

β-Sialon bonded ZrO2 composites were prepared by reaction sintering process using β-Sialon and CaO stabilized ZrO2 powders as raw materials.The effect of β-Sialon powder additions on the properties of the composites was investigated. The results show that the samples with 10 wt% of β-Sialon addition had the lowest apparent porosity (29.80%) and the highest of flexural strength (68.70MPa). The thermal shock resistance in carbon addition of the composites could be improved by addtion of 5wt% β-Sialon. It may be relative with that the sample had the lowest thermal expansion coefficient in vacuum.

scholarly journals EVALUATION AND CHARACTERIZATION OF GAKEM AND ABOUCHICHE CLAY SAMPLES IN BEKWARRA LGA OF CROSS RIVER STATE FOR USE AS REFRACTORY MATERIALS

2017 ◽  
Vol 36 (3) ◽  
pp. 844-848
Author(s):  
FA Ovat ◽  
DE Ewa ◽  
EA Egbe
Keyword(s):  
Bulk Density ◽  
Thermal Shock ◽  
Thermal Shock Resistance ◽  
Linear Shrinkage ◽  
Apparent Porosity ◽  
Refractory Materials ◽  
Crushing Strength ◽  
Cold Crushing Strength ◽  
Shock Resistance

The characterization of some clay as refractory materials for furnace lining has become relevant to find solutions to the cost involved in the purchase and importation of these refractory materials. This work investigated the refractory properties of clay samples for their suitability for use in the industries. Clay samples were collected from Gakem and Abouchiche areas and analysed for physical and chemical properties to determine the suitability of the clays as refractory materials. The results showed cold crushing strength (21.46MN/m2), thermal shock resistance (27 cycles), bulk density (3.52g/cm3), linear shrinkage(3.80%), apparent porosity (28.84%) and permeability (80%) for Gakem; and cold cold crushing strength (18.40MN/m2), thermal shock resistance (25 cycles), bulk density(2.81g/cm3), linear shrinkage (3.70%), apparent porosity (25.86%) and permeability (77%) for Abouchiche respectively. The chemical compositions of these clay samples were also investigated. The results showed that the samples fall under Aluminosilicate type of clay because of their high values of Aluminium Oxide and Silicon Oxide. Tests showed that clay from these areas can be used to produce refractory materials that can withstand a furnace temperature of about 1600°C. http://dx.doi.org/10.4314/njt.v36i3.26

Sign in / Sign up

Export Citation Format

Share Document