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.

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.

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.

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.

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.

Effect of Forming Pressure and Sintering Temperature on Thermal Expansion Property of Li2O-Al2O3-P2O5-SiO2 Glass-Ceramics

2011 ◽  
Vol 197-198 ◽  
pp. 436-439
Author(s):  
Min Hua Luo ◽  
Zhuo Hao Xiao
Keyword(s):  
Thermal Expansion ◽  
Sintering Temperature ◽  
Coefficient Of Thermal Expansion ◽  
Sol Gel ◽  
Glass Ceramics ◽  
Thermal Expansion Property ◽  
Expansion Property ◽  
Prepared Glass

Li2O-Al2O3-P2O5-SiO2 xerogel powders were synthesized by sol-gel route and glass-ceramics were prepared under different forming pressure and sintering temperature. The effects of sintering temperature and forming pressure on coefficient of thermal expansion of prepared glass-ceramics were investigated by means of DTA-TG, TEC and XRD. The results indicate that xerogel powders crystallization begins at 785°C, and the main crystallite phases in the researched specimens are virgilite and cristobalite. The TEC decreases linearly with the forming pressure. When the sintering temperature is 950°C and forming pressure is 40MPa, a low TEC of 0.65×10-6 °C-1 can be obtained.

NILO ALLOY 36

Alloy Digest ◽  
1987 ◽  
Vol 36 (8) ◽  
Keyword(s):  
Thermal Expansion ◽  
Corrosion Resistance ◽  
High Temperature ◽  
Physical Properties ◽  
Surface Treatment ◽  
Constant Coefficient ◽  
Coefficient Of Thermal Expansion ◽  
Heat Treating ◽  
Temperature Performance ◽  
Iron Nickel

Abstract NILO alloy 36 is a binary iron-nickel alloy having a very low and essentially constant coefficient of thermal expansion at atmospheric temperatures. This datasheet provides information on composition, physical properties, elasticity, and tensile properties. It also includes information on high temperature performance and corrosion resistance as well as forming, heat treating, machining, joining, and surface treatment. Filing Code: Fe-79. Producer or source: Inco Alloys International Inc..

UNISPAN LR35

Alloy Digest ◽  
1971 ◽  
Vol 20 (1) ◽  
Keyword(s):  
Thermal Expansion ◽  
Corrosion Resistance ◽  
High Temperature ◽  
Physical Properties ◽  
Surface Treatment ◽  
Tensile Properties ◽  
Coefficient Of Thermal Expansion ◽  
Heat Treating ◽  
Temperature Performance ◽  
Operational Level

Abstract UNISPAN LR35 offers the lowest coefficient of thermal expansion of any alloy now available. It is a low residual modification of UNISPAN 36 for fully achieving the demanding operational level of precision equipment. This datasheet provides information on composition, physical properties, hardness, and tensile properties. It also includes information on high temperature performance and corrosion resistance as well as forming, heat treating, machining, and surface treatment. Filing Code: Fe-46. Producer or source: Cyclops Corporation.

DELTALLOY 4032

Alloy Digest ◽  
1998 ◽  
Vol 47 (4) ◽  
Keyword(s):  
Wear Resistance ◽  
Thermal Expansion ◽  
Physical Properties ◽  
Surface Treatment ◽  
Tensile Properties ◽  
Surface Finish ◽  
Coefficient Of Thermal Expansion ◽  
Single Point ◽  
High Strength ◽  
Corrosion And Wear

Abstract Deltalloy 4032 has good machinability and drilling characteristics when using single-point or multispindle screw machines and an excellent surface finish using polycrystalline or carbide tooling. The alloy demonstrates superior wear resistance and may eliminate the need for hard coat anodizing. Deltalloy 4032 is characterized by high strength and a low coefficient of thermal expansion. This datasheet provides information on composition, physical properties, and tensile properties. It also includes information on corrosion and wear resistance as well as machining and surface treatment. Filing Code: AL-347. Producer or source: ALCOA Wire, Rod & Bar Division.

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