Modification of Porous Cordierite Ceramic

2016 ◽  
Vol 721 ◽  
pp. 322-326
Author(s):  
Ruta Švinka ◽  
Visvaldis Svinka ◽  
Julija Bobrovik
Keyword(s):  
Compressive Strength ◽  
Thermal Expansion ◽  
Large Scale ◽  
Sintering Temperature ◽  
Coefficient Of Thermal Expansion ◽  
Slip Casting ◽  
Concentrated Suspension ◽  
Cordierite Ceramic ◽  
Silica Additive ◽  
Porous Cordierite

Highly porous cordierite ceramic by using of talcum, kaolinite and γ-alumina was obtained by method of slip casting of concentrated suspension. Additives of amorphous silica and non-stabilized zirconia in the amount of 5 wt% were used. Sintering temperature of dried samples was in range of 1250 – 1450°C. All the samples contain crystalline phases of cordierite, mullite and corundum but, depending on the additives, as a result of sintering in addition forms spinel, cristobalite or zircon (ZrSiO4). Porosity of obtained materials changes in large scale from 42 to 59 per cent; it is influenced by both sintering temperature and composition. Compressive strength increases with the addition of zirconia. In comparison, compressive strength of samples without additives or with silica additive does not exceed 3.5 MPa. The increase of coefficient of thermal expansion depends both on the composition and sintering temperature. ZrO2 additive increases the coefficient of thermal expansion considerably.

Influence of Technological Parameters on Thermal Properties of Cordierite Ceramics

2018 ◽  
Vol 762 ◽  
pp. 300-305
Author(s):  
Maris Rundans ◽  
Gaida Sedmale ◽  
Aija Krūmiņa ◽  
Aiga Ivdre
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Thermal Properties ◽  
Sintering Temperature ◽  
Phase Content ◽  
Technological Parameters ◽  
Cordierite Ceramic ◽  
Ceramic Samples ◽  
Cordierite Ceramics ◽  
Porous Cordierite

Porous cordierite ceramic samples have been prepared by using 33% of two carbonate-containing illite clays as substitutes for the necessary synthetic ingredients. The changes of thermal (CTE) and mechanical properties (compressive strength, modulus of elasticity), as well as phase content, apparent porosity and bulk density have been investigated in regards to gradual changes in maximum sintering temperature. It can be affirmed that these properties strongly depend on the thermal parameters of sintering as well as slightly upon differences in chemical composition of composition substitutes.

scholarly journals Sintering Behavior, Thermal Expansion, and Environmental Impacts Accompanying Materials of the Al2O3/ZrO2 System Fabricated via Slip Casting

Materials ◽  
2021 ◽  
Vol 14 (12) ◽  
pp. 3365
Author(s):  
Justyna Zygmuntowicz ◽  
Magdalena Gizowska ◽  
Justyna Tomaszewska ◽  
Paulina Piotrkiewicz ◽  
Radosław Żurowski ◽  
...  
Keyword(s):  
Thermal Expansion ◽  
Life Cycle ◽  
Coefficient Of Thermal Expansion ◽  
Raw Materials ◽  
Slip Casting ◽  
Ceramic Materials ◽  
Sintering Behavior ◽  
Environmental Loads ◽  
Practical Applications ◽  
Technical Ceramics

This work focuses on research on obtaining and characterizing Al2O3/ZrO2 materials formed via slip casting method. The main emphasis in the research was placed on environmental aspects and those related to the practical use of ceramic materials. The goal was to analyze the environmental loads associated with the manufacturing of Al2O3/ZrO2 composites, as well as to determine the coefficient of thermal expansion of the obtained materials, classified as technical ceramics. This parameter is crucial in terms of their practical applications in high-temperature working conditions, e.g., as parts of industrial machines. The study reports on the four series of Al2O3/ZrO2 materials differing in the volume content of ZrO2. The sintering process was preceded by thermogravimetric measurements. The fabricated and sintered materials were characterized by dilatometric study, scanning electron microscopy, X-ray diffraction, and stereological analysis. Further, life cycle assessment was supplied. Based on dilatometric tests, it was observed that Al2O3/ZrO2 composites show a higher coefficient of thermal expansion than that resulting from the content of individual phases. The results of the life cycle analysis showed that the environmental loads (carbon footprint) resulting from the acquisition and processing of raw materials necessary for the production of sinters from Al2O3 and ZrO2 are comparable to those associated with the production of plastic products such as polypropylene or polyvinyl chloride.

Fabrication and Characterization of Low Thermal Expansion Cordierite/Spodumene/Mullite Composite Ceramic for Cookware

2018 ◽  
Vol 766 ◽  
pp. 276-281
Author(s):  
Pranee Junlar ◽  
Thanakorn Wasanapiarnpong ◽  
Lada Punsukmtana ◽  
Noppasint Jiraborvornpongsa
Keyword(s):  
Thermal Expansion ◽  
Water Absorption ◽  
Thermal Expansion Coefficient ◽  
Expansion Coefficient ◽  
Coefficient Of Thermal Expansion ◽  
Slip Casting ◽  
Ceramic Composites ◽  
Modulus Of Rupture ◽  
Mullite Phase ◽  
Low Thermal Expansion

Ceramic cookware can be taken a direct flame or stove top for the duration without damage. The selected materials must have low thermal expansion coefficient, high strength, low water absorption and high thermal shock resistance, reasonable in cost and easy to be produced. Cordierite and spodumene composite has been interested for ceramic cookware due to their fitted properties. In previous work, study in the cordierite-spodumene composite with low thermal expansion coefficient of 2.60 x 10-6 /°C when sintered at 1250 oC with a ratio of spodumene 60 wt% and cordierite 40 wt% can withstand the pot shape samples. However, the sample showed relatively high water absorption and low strength which was not appropriate for using in this application. In this research, mullite is added in the formula to improve strength and densification of ceramic composites. Spodumene, ball clay, calcined talc and calcined alumina are used as starting raw materials and formed by slip casting. All samples are sintered in a temperature range from 1250-1275 °C in an electric furnace. Water absorption and bulk density were tested by Archimedes method, modulus of rupture was tested by the three-point bending method, microstructure were investigated by SEM and the coefficient of thermal expansion was measured by dilatometer. It was found that the mullite phase was investigated when adding mullite more than 30 wt% in cordierite-spodumene composite.

The Effect of Sintering Temperature on Physical Properties of Leucite Ceramics

2019 ◽  
Vol 891 ◽  
pp. 214-218
Author(s):  
Jirasak Tharajak ◽  
Noppakun Sanpo
Keyword(s):  
Thermal Expansion ◽  
Research Study ◽  
Sintering Temperature ◽  
Coefficient Of Thermal Expansion ◽  
Raw Materials ◽  
Sol Gel ◽  
Physical Property ◽  
Dental Ceramics ◽  
Ceramic Particles ◽  
Sol Gel Process

Leucite has been widely used as a constituent of dental ceramics to modify the coefficient of thermal expansion. This is most important where the ceramic is to be fused or baked onto metal. However, its physical property was unpredictable since it was sensitive to several parameters such as sintering temperature and concentration of raw materials. In this research study, leucite ceramic particles were synthesized by in-house sol-gel process. The morphology and size of our synthesized leucite particles were analyzed by SEM, vicker hardness and XRD, respectively. It was revealed that the sintering temperature played the important role on several properties of leucite ceramic particles.

Evaluation of a New Low Thermal Expansion Creep Resistant Nickel-Based Alloy

2007 ◽  
Author(s):  
Paul D. Jablonski ◽  
Karol K. Schrems
Keyword(s):  
Power Generation ◽  
Thermal Expansion ◽  
Large Scale ◽  
Thermal Stresses ◽  
Coefficient Of Thermal Expansion ◽  
Ferritic Steels ◽  
Chemical Processing ◽  
Large Scale Systems ◽  
Low Thermal Expansion ◽  
Nickel Based Alloy

For many large-scale systems such as land-based power generation and chemical processing facilities, stresses due to thermal expansion can become a significant consideration in system design. Additionally, differential thermal stresses result from materials such as ferritic steels used in conjunction with nickel-based superalloys. An experimental nickel-based alloy designed for low CTE (Coefficient of Thermal Expansion) has been evaluated for creep performance and is compared to other low CTE nickel-based alloys. The creep results of this new alloy compare favorably to other low CTE nickel-based alloys.

Sintering of Cordierite–borosilicate Glass Composites

2000 ◽  
Vol 15 (8) ◽  
pp. 1759-1765 ◽  
Author(s):  
Jiin-Jyh Shyu ◽  
Jui-Kai Wang
Keyword(s):  
Thermal Expansion ◽  
Borosilicate Glass ◽  
Sintering Temperature ◽  
Coefficient Of Thermal Expansion ◽  
High Viscosity ◽  
Glass Composites ◽  
Density Reduction ◽  
Low Viscosity ◽  
The Difference ◽  
Typical Range

The sintering and properties of cordierite–borosilicate glass composites were investigated. For the composites with ≥35% low-viscosity glass, the sintered densities decreased with the increasing sintering temperature above 850 °C. No crystallization of the glass was found. For the composites with 50–90 wt% high-viscosity glass, the sintered densities remained nearly constant (>95%) in a wide sintering temperature range. However, cristobalite crystallized from the glass phase, resulting in an undesirably high coefficient of thermal expansion. Presintering processing and a lower heating rate improved the densification of the composites with low-viscosity glass while limiting that of the composites with high-viscosity glass. This result is explained by the difference in crystallizability between these two glasses. As low- and high-viscosity glass powders were simultaneously added, the density reduction was reduced and the coefficient of thermal expansion was closer to that of Si because of the absence of cristobalite phase. The dielectric constant of all the composites was in the typical range of 4.9–5.7 at 1 MHz.

Effect of Different Sintering Temperature on the Performance of Mullite-Corundum Refractory Materials

2013 ◽  
Vol 750-752 ◽  
pp. 521-524
Author(s):  
Ping Li ◽  
Xing Yong Gu ◽  
Ting Luo ◽  
Yun Xia Chen
Keyword(s):  
Thermal Expansion ◽  
Thermal Stress ◽  
Stress Fracture ◽  
Bending Strength ◽  
Sintering Temperature ◽  
Coefficient Of Thermal Expansion ◽  
Refractory Materials ◽  
Corundum Refractory ◽  
X Ray Diffraction

Al (OH)3, Suzhou kaolin, AlF3 and V2O5 were premixed and pelleted to form the precursor for fabricating the mullite whisker, and then the precursor was added into the calcined bauxite and Suzhou kaolin mixture according to a certain mass percent. The mullite-corundum refractory materials with well-dispersed needle-like mullite formed in-situ were prepared. Through studying the effect of different sintering temperatures on the performances of the as-fabricated mullite-corundum refractory materials, it was concluded that the appropriate sintering temperature was 1450 °C. X-ray diffraction (XRD), scanning electron microscopy (SEM), water absorption, bending strength, coefficient of thermal expansion and the first thermal stress fracture factor were used to characterize and evaluate the materials. The results show that the sintering character and thermal expansion coefficient of the refractory materials increase with the rising sintering temperature. The bending strength of the refractory materials sintered at 1500 °C presented the maximum value and the first thermal stress fracture factor appeared the highest value at 1450 °C.

Calculation of Effective Coefficient of Thermal Expansion for Composite ‘Glass-Eucryptite’ Changing during Sintering

2015 ◽  
Vol 756 ◽  
pp. 372-377
Author(s):  
Anna G. Knyazeva ◽  
Olga N. Kryukova ◽  
Kirill S. Kostikov
Keyword(s):  
Thermal Expansion ◽  
Effective Properties ◽  
Sintering Temperature ◽  
Coefficient Of Thermal Expansion ◽  
Spherical Inclusion ◽  
Zone Formation ◽  
Composite Glass ◽  
Quantitative Results ◽  
Transient Zone ◽  
Composite Properties

In this work, thermal expansion coefficient of composite is calculated on the base of the model transient zone formation between spherical inclusion and matrix. Effective properties of particle surrounded by transient zone are used when composite properties are calculated. Different models leads to qualitative results similar to each other. Quantitative results depend on sintering temperature and time, on inclusion sizes and volume part of inclusions.

scholarly journals Effect of Stir Casting Process Parameters on Properties of Aluminium Composites – Taguchi’s Analysis

2019 ◽  
Vol 25 (4) ◽  
pp. 401-406
Author(s):  
Hemalatha ARIHARAPUTHIRAN ◽  
Dhanalakshmi VENKADASAMY
Keyword(s):  
Compressive Strength ◽  
Thermal Expansion ◽  
Process Parameters ◽  
Sliding Wear ◽  
Coefficient Of Thermal Expansion ◽  
Stir Casting ◽  
Processing Temperature ◽  
Wear Property ◽  
Casting Method ◽  
Abrasion Wear

The need for lightweight materials in various industries, increased fuel price, requirement of improved mechanical, thermal properties leads to the development of aluminium metal matrix composites. Stir casting method is employed for preparing composite consisting of aluminium die casting -12 alloy and reinforcement of 10 % by weight proportion of silicon carbide. Taguchi’s experimental analysis is employed for varying the process parameters of stir casting method like process temperature, stirring time and stirring speed. Tests were conducted to measure mechanical property like compressive strength, wear property such as sliding wear, micro abrasion and thermal property like coefficient of thermal expansion.  An attempt has been made to study the unrelated properties like compressive strength, sliding wear resistance, micro abrasion wear and coefficient of thermal expansion of aluminium composites by Principal Component Analysis method. The experimental investigation shows that increase in processing temperature reduces sliding wear, micro abrasion wear and coefficient of thermal expansion and also increases compressive strength.

Method to Determine Maximum Allowable Sinterable Silver Interconnect Size

2016 ◽  
Vol 2016 (HiTEC) ◽  
pp. 000207-000215 ◽  
Author(s):  
A. A. Wereszczak ◽  
M. C. Modugno ◽  
S. B. Waters ◽  
D. J. DeVoto ◽  
P. P. Paret
Keyword(s):  
Silicon Carbide ◽  
Thermal Expansion ◽  
Room Temperature ◽  
Sintering Temperature ◽  
Coefficient Of Thermal Expansion ◽  
Bonding Temperature ◽  
Heat Sinks ◽  
Large Area ◽  
Electrical Conductivities ◽  
Sintered Silver

Abstract The use of sintered-silver for large-area interconnection is attractive for some large-area bonding applications in power electronics such as the bonding of metal-clad, electrically-insulating substrates to heat sinks. Arrays of different pad sizes and pad shapes have been considered for such large area bonding; however, rather than arbitrarily choosing their size, it is desirable to use the largest size possible where the onset of interconnect delamination does not occur. If that is achieved, then sintered-silver's high thermal and electrical conductivities can be fully taken advantage of. Toward achieving this, a simple and inexpensive proof test is described to identify the largest achievable interconnect size with sinterable silver. The method's objective is to purposely initiate failure or delamination. Copper and invar (a ferrous-nickel alloy whose coefficient of thermal expansion (CTE) is similar to that of silicon or silicon carbide) disks were used in this study and sinterable silver was used to bond them. As a consequence of the method's execution, delamination occurred in some samples during cooling from the 250°C sintering temperature to room temperature and bonding temperature and from thermal cycling in others. These occurrences and their interpretations highlight the method's utility, and the herein described results are used to speculate how sintered-silver bonding will work with other material combinations.

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