Incorporation of Aluminium Residues in Dense Cordierite Formulations

2006 ◽  
Vol 514-516 ◽  
pp. 1722-1725 ◽  
Author(s):  
Fernando A. Costa Oliveira ◽  
Francisco Delmas ◽  
Ana Araújo ◽  
Jorge Cruz Fernandes ◽  
Diamantino Dias
Keyword(s):  
Thermal Expansion ◽  
Environmental Impact ◽  
Flexural Strength ◽  
Thermal Shock Resistance ◽  
Thermal Expansion Coefficients ◽  
Lower Thermal Expansion ◽  
Shock Resistance ◽  
Expansion Coefficients ◽  
Α Al2o3 ◽  
Batch Formulation

Additions of γ-Al2O3 and Al(OH)3 powders produced at INETI from spent baths resulting from the aluminium transformation industry were made to a commercial cordierite batch formulation (without Al2O3 addition), known as DC4, developed by Rauschert Portuguesa Lda., in order to evaluate the possibility of replacing with benefits the conventional α-Al2O3 source used. The resulting samples were found to be denser than the commercial ones. This is related to the higher reactivity of these particular sources of alumina as compared to that added to the commercial product. Consequently, higher Young’s modulus (100-114 GPa) and flexural strength (80-98 MPa) were achieved for the developed materials in comparison to those obtained for commercial cordierite (96±2 GPa and 67±5 MPa, respectively). In addition, slightly lower thermal expansion coefficients were observed (3.6x10-6 K-1) and the thermal shock resistance was found to increase from 325 K to 350 K. The developed technology can be regarded as suitable for reducing the environmental impact of deposition of wastes from the aluminium transformation industry.

Properties of ZrO2/Glass-Ceramics Composite

2007 ◽  
Vol 280-283 ◽  
pp. 995-998
Author(s):  
Y.M. Zhu ◽  
Xia Wan Wu ◽  
Zhi Hong Li
Keyword(s):  
Thermal Expansion ◽  
Flexural Strength ◽  
Glass Powder ◽  
Sintering Temperature ◽  
Raw Materials ◽  
Glass Ceramics ◽  
Glass Content ◽  
Thermal Expansion Coefficients ◽  
Lower Thermal Expansion ◽  
Expansion Coefficients

In order to reduce the raw materials cost, lower the sintering temperature of 3Y-TZP optical fiber ferrules, the 3Y-TZP/ LAS glass ceramics composites were prepared and their properties were investigated in this paper. The results showed that the sintering temperatures and thermal expansion coefficients of the 3Y-TZP/LAS glass ceramics composites were lowered with the increase of glass content. The flexural strength of the composites were decreased with the increase of glass content, but the flexural strength of the composite with 15% weight glass was higher than 400MPa. The LAS glass powder added into the composites was crystallized and b-spodumene s.s was precipitated. during sintering. The b-spodumene s.s. having lower thermal expansion coefficient and higher strength was beneficial to reduce thermal expansion coefficients and keep higher strengths of the composites .

Thermal Expansion Properties of Plasma-Sprayed Thick Coatings

1998 ◽  
Author(s):  
Y.-K. Lee ◽  
H.-J. Kim ◽  
R.-W. Chang
Keyword(s):  
Thermal Expansion ◽  
Phase Transformation ◽  
Thermal Shock ◽  
Thermal Shock Resistance ◽  
Powder Size ◽  
Thermal Expansion Coefficients ◽  
Shock Resistance ◽  
Expansion Coefficients ◽  
Plasma Sprayed ◽  
Thick Coatings

Abstract The thermal expansion characteristics of plasmasprayed coatings were investigated. The thermal expansion measurements were carried out up to 1200°C on thick coatings that were substrate free. The effects on the thermal expansion coefficients were studied in terms of composition, powder size, porosity, and the phase transformation. The relationships between the thermal shock resistance and the thermal expansion properties of the coatings are also discussed.

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.

The Effect of Alumina (Al2O3) on the Characteristics of Sintered Mullite-Cordierite Ceramics Synthesized with Kaolin from Naratiwas of Thailand

2016 ◽  
Vol 690 ◽  
pp. 65-70 ◽  
Author(s):  
Santi Pongphot ◽  
Sakdiphon Thiansem
Keyword(s):  
Mechanical Properties ◽  
Thermal Expansion ◽  
Flexural Strength ◽  
Bulk Density ◽  
Suitable Condition ◽  
Length Change ◽  
Hydraulic Press ◽  
Thermal Expansion Coefficients ◽  
Expansion Coefficients ◽  
Cordierite Ceramics

Mullite-cordierite ceramics was prepared by the three composition of talc, kaolin (kaolin from Naratiwas in Thailand) (NT) and alumina. The different amounts of alumina (5, 10, 15 and 20 wt%) were added to produce various mullite-cordierite alumina mixtures which are denoted as NA, NB, NC and ND, respectively. The mixtures were pressed into rectangular shapes by hydraulic press with the pressure of 150 kg/cm2 then sintered at temperature of 1300 °C and 1350 °C for 2 hours. The morphology of the synthesized mullite-cordierite samples were characterized by x-ray diffraction spectroscopy (XRD), and physical-mechanical properties were investigated. Mullite-cordierite was successfully synthesized. The XRD result was represented phases of mullite and cordierite. The NA samples sintered at temperature of 1300 °C indicated the best physical-mechanical properties including bulk density (2.23 g/cm3), flexural strength (44.4 MPa) and thermal expansion coefficients (5.00x10-6). The other NA samples sintered at temperature of 1350 °C exhibited the bulk density, flexural strength and thermal expansion coefficients are 2.21 g/cm3, 47.8 MPa and 4.99 x10-6, respectively. The thermal expansion coefficient of the NT sintered samples have been plotted the length change relative to measuring temperature ranging of 30-1200 °C. The suitable condition of the synthesized mullite-cordierite ceramics is finally obtained the NA samples with 5 percent weight of alumina composition sintered at the temperature of 1350 °C.

Effect of SiC on Microstructures and Properties of Cordierite-Mullite Multiphase Ceramics Material

2009 ◽  
Vol 620-622 ◽  
pp. 33-36
Author(s):  
Jian Guang Bai ◽  
Bo Wang ◽  
Guang Liang Liu ◽  
Ji Qiang Gao ◽  
Jian Feng Yang ◽  
...  
Keyword(s):  
Thermal Expansion ◽  
Electron Microscope ◽  
Flexural Strength ◽  
Thermal Shock ◽  
Thermal Shock Resistance ◽  
Fused Silica ◽  
Fracture Surface Morphology ◽  
Shock Resistance ◽  
Scanning Electron ◽  
Multiphase Ceramics

In this paper, cordierite-mullite multiphase ceramics material was prepared using cordierite powder, mullite particles, fused silica, magnesia and alumina as main starting material. Effects of addition of 2%~10% SiC on the thermal expansion, flexural strength and thermal shock resistance were studied, and the fracture surface morphology was observed with Scanning Electron Microscope (SEM). The results showed that the multiphase ceramics material’s thermal expansion coefficient and flexural strength had little change. The thermal shock resistance of cordierite-mullite multiphase ceramics material varied as increasing-decreasing with the increase of SiC content, when the content of SiC was as high as 4%, the highest conservation rate of the flexural strength after 1100°C~water(3 times) was 72.08%, and the thermal shock resistance of cordierite-mullite multiphase ceramics material was superior.

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.

Properties of Waste Derived Mullite

2007 ◽  
Vol 544-545 ◽  
pp. 605-608 ◽  
Author(s):  
U.Sangwanna Sanewirush ◽  
M. Buaheepkaew ◽  
O. Kosasang ◽  
P. Saewong
Keyword(s):  
Thermal Expansion ◽  
Flexural Strength ◽  
Thermal Shock Resistance ◽  
Power Plants ◽  
Alkaline Earth ◽  
Rice Husk Ash ◽  
Slip Casting ◽  
Structural Water ◽  
Alkaline Earth Elements ◽  
Shock Resistance

Waste sediment (WS) from three different aluminum factories and rice husk ash (RHA) from power plants are used as precursors. Each WS is calcined to remove structural water then mixed and wet milled with RHA by 70 wt% until a homogeneous slip is obtained. The samples are formed by means of slip casting in plaster molds and fired at 1400 °C for 2 hours. The fired samples normally contain ~94 wt% mullite, 6 wt% residual silica and small amount of oxides of alkali and alkaline earth elements. It is found that their density and flexural strength are affected by alkali and alkaline earth contents and generally range from 1.53 to 2.38 g/cm3 and 18.11 to 76.37 MPa, respectively. While thermal expansion coefficient varies from 5.78 x 10-6 to 8.16 x 10-6 /°C and thermal shock resistance (T) from =200 to 300 °C.

scholarly journals Preparation of Al2TiO5 ceramic fibers and thermal expansion, insulation, and strength of ZrO2-Al2TiO5 fiberboards

2021 ◽  
Author(s):  
Wei Liu ◽  
Yongshuai Xie ◽  
Zhezhe Deng ◽  
Ying Peng ◽  
Jianhong Dong ◽  
...  
Keyword(s):  
Thermal Expansion ◽  
High Temperature ◽  
Thermal Shock ◽  
Thermal Insulation ◽  
Thermal Shock Resistance ◽  
Single Phase ◽  
Sol Gel ◽  
Ceramic Fibers ◽  
Thermal Expansion Coefficients ◽  
Shock Resistance

Abstract In the field of thermal insulation, Zirconia (ZrO2) fiber and its products have high thermal expansion coefficients and poor thermal shock resistance, which leads to great challenges in the industry. In this work, aluminum titanate (Al2TiO5) single-phase ceramic fibers were prepared by a sol-gel method, using polyacetylacetone titanium-aluminum (PAAT) as the precursors with electrospinning technology. The single-phase Al2TiO5 fibers exhibited excellent high-temperature resistance, and maintained fibers morphology at a high temperature of 1500 ºC. Next, ZrO2-Al2TiO5 (ZAT) fiberboards were prepared by mixing ZrO2 fibers and Al2TiO5 fibers. The mixture was heat-treated to 1500 ºC to prepare the ZAT fiberboards. Characterization results indicated that the contents of Al2TiO5 fibers have obvious effects on the performance of thermal insulation, strength, thermal expansion, and thermal shock resistance. Particularly, the thermal expansion coefficient of ZAT-8 fiberboards was about 20% lower than that of ZAT-0 fiberboards. These attractive characteristics might give ZAT fiberboards enormous potential in the field of high-temperature insulation.

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