Thermal properties of silica. Part 2.—Thermal expansion coefficient of vitreous silica

1966 ◽  
Vol 62 (0) ◽  
pp. 1505-1510 ◽  
Author(s):  
P. H. Gaskell
Keyword(s):  
Thermal Expansion ◽  
Thermal Properties ◽  
Thermal Expansion Coefficient ◽  
Expansion Coefficient ◽  
Vitreous Silica

Design, Preparation and Thermal Properties of (La0.4Sm0.5Yb0.1)2Zr2O7 Ceramic for Thermal Barrier Coatings

2012 ◽  
Vol 512-515 ◽  
pp. 469-473 ◽  
Author(s):  
L. Liu ◽  
Z. Ma ◽  
F.C. Wang ◽  
Q. Xu
Keyword(s):  
Thermal Conductivity ◽  
Thermal Expansion ◽  
Thermal Properties ◽  
Rare Earth ◽  
Thermal Expansion Coefficient ◽  
Thermal Barrier Coatings ◽  
Expansion Coefficient ◽  
Phonon Transport ◽  
Thermal Barrier ◽  
Barrier Coatings

According to the theory of phonon transport and thermal expansion, a new complex rare-earth zirconate ceramic (La0.4Sm0.5Yb0.1)2Zr2O7, with low thermal conductivity and high thermal expansion coefficient, has been designed by doping proper ions at A sites. The complex rare-earth zirconate (La0.4Sm0.5Yb0.1)2Zr2O7 powder for thermal barrier coatings (TBCs) was synthesized by coprecipitation-calcination method. The phase, microstructure and thermal properties of the new material were investigated. The results revealed that single phase (La0.4Sm0.5Yb0.1)2Zr2O7 with pyrochlore structure was synthesized. The thermal conductivity and the thermal expansion coefficient of the designed complex rare-earth zirconate ceramic is about 1.3W/m•K and 10.5×10-6/K, respectively. These results imply that (La0.4Sm0.5Yb0.1)2Zr2O7 can be explored as the candidate material for the ceramic layer in TBCs system.

scholarly journals Thermal Properties of Stabilized Zirconia at Low Temperatures

1985 ◽  
Vol 38 (4) ◽  
pp. 617 ◽  
Author(s):  
JG Collins ◽  
SJ Collocott ◽  
GK White
Keyword(s):  
Heat Capacity ◽  
Thermal Expansion ◽  
Thermal Properties ◽  
Thermal Expansion Coefficient ◽  
Expansion Coefficient ◽  
Low Temperatures ◽  
Linear Thermal Expansion Coefficient ◽  
Linear Thermal Expansion ◽  
Stabilized Zirconia ◽  
Elastic Data

The linear thermal expansion coefficient a from 2 to 100 K and heat capacity per gram cp from 0�3 to 30 K are reported for fully-stabilized zirconia containing a nominal 16 wt.% (9 mol.%) of yttria. The heat capacity below 7 K has been analysed into a linear (tunnelling?) term, a Schottky term centred at 1�2 K, a Debye term (e~ = 540 K), and a small T5 contribution. The expansion coefficient is roughly proportional to T from 5 to 20 K and gives a limiting lattice Griineisen parameter 'Yo ::::: 5, which agrees with that calculated from elastic data.

Physical Properties of Plastics for Photothermoelastic Investigations

1958 ◽  
Vol 25 (4) ◽  
pp. 525-528
Author(s):  
H. Tramposch ◽  
G. Gerard
Keyword(s):  
Thermal Expansion ◽  
Thermal Properties ◽  
Heat Conduction ◽  
Physical Properties ◽  
Epoxy Resin ◽  
Thermal Expansion Coefficient ◽  
Expansion Coefficient ◽  
Modulus Of Elasticity ◽  
Figures Of Merit ◽  
Optical Sensitivity

Abstract The optical and physical properties of Paraplex P43, Castolite, and epoxy resin Hysol 6000-OP, which are potentially of interest in photothermoelastic investigations, were investigated over a temperature range from +100 to −60 F. Results on the thermal-expansion coefficient, the material fringe value, and the modulus of elasticity as functions of temperature are presented. Also evaluated were thermal properties of importance in heat conduction. Photothermoelastic figures of merit, which rate the optical sensitivity of materials in photothermoelastic applications, as well as a new method to determine this figure in a relative manner are presented.

Thermal Properties of Simulated High Burn up Nitride Fuels and Nitride ADS Targets

2007 ◽  
Vol 1043 ◽  
Author(s):  
Masayoshi Uno ◽  
Ken Kurosaki ◽  
Shinsuke Yamanaka ◽  
Kazuo Minato
Keyword(s):  
Thermal Conductivity ◽  
Solid Solution ◽  
Thermal Expansion ◽  
Thermal Properties ◽  
Grain Boundaries ◽  
Thermal Expansion Coefficient ◽  
Expansion Coefficient ◽  
Lattice Parameter ◽  
Nitride Fuels ◽  
Mo Content

AbstractWe made various nitride fuels containing simulated FP elements and evaluated the effect of these FP elements on the properties of the nitrides. For Uranium Neodymium nitride solid solution the lattice parameter increased with Nd content, thermal expansion coefficient did not change and thermal conductivity decreased with Nd content. The thermal expansion for Pd containing UN, where Pd precipitated as UPd3 in the grain boundaries of UN, was nearly the same as that of UN and the thermal conductivity for Pd containing in the UN matrix decreased with Pd content. For Mo containing UN Mo precipitated as Mo metal isotropically. Both the thermal expansion and thermal conductivity did not vary with Mo content This might result from the low Mo contents at these simulated burnups.

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.

Study on Electrical and Thermal Properties of Epoxy Resin/Inorganic Filler Composites for the Fully Enclosed Casting Bus Bar and its Calculation of the Temperature Field

2014 ◽  
Vol 804 ◽  
pp. 191-194 ◽  
Author(s):  
Nai Kui Gao ◽  
Yi Li Wang ◽  
Wen Xi Zhang ◽  
Zhao Liu ◽  
Chi Chen ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Thermal Expansion ◽  
Temperature Field ◽  
Thermal Properties ◽  
Epoxy Resin ◽  
Thermal Expansion Coefficient ◽  
Expansion Coefficient ◽  
Room Temperature ◽  
Inorganic Filler ◽  
Study Results

This paper focused on the epoxy resin/inorganic filler composites. The electrical and thermal properties of the composites were tested and analyzed at room temperature. The influence of temperature on the thermal conductivity and thermal expansion coefficient was studied. Based on the electrical and thermal properties of the composites, the simulation model of the fully enclosed epoxy resin casting bus bar (FEERCB) was built, and the temperature field distribution of the FEERCB was calculated. T The study results showed that the volume resistivity, dielectric constant, dielectric loss factor and breakdown strength of the epoxy resin/inorganic filler composites were 1.74×1014Ω·cm, 3.44, 3.75 and 22.31 kV/mm respectively at room temperature. The thermal conductivity and thermal expansion coefficient of the composites were 2.55 W/m·K and 21.73×10-6 /°C, achieved the insulation requirements for FEERCB. In the temperature range of the test, with increasing temperature, the thermal conductivity reduced gradually, while the thermal expansion coefficient increased gradually. The simulation results showed that the FEERCB has remarkable performance on the heat dissipation and current carrying capability.

scholarly journals Effect of ZnO on the Thermal Properties of Tellurite Glass

2013 ◽  
Vol 2013 ◽  
pp. 1-6 ◽  
Author(s):  
H. A. A. Sidek ◽  
S. Rosmawati ◽  
B. Z. Azmi ◽  
A. H. Shaari
Keyword(s):  
Thermal Expansion ◽  
Glass Transition ◽  
Thermal Properties ◽  
Thermal Expansion Coefficient ◽  
Debye Temperature ◽  
Expansion Coefficient ◽  
Glass Sample ◽  
Tellurite Glass ◽  
Softening Temperature ◽  
Tellurite Glasses

Systematic series of binary zinc tellurite glasses in the form(ZnO)x(TeO2)(wherex=0to 0.4 with an interval of 0.05 mole fraction) have been successfully prepared via conventional melt cast-quenching technique. Their density was determined by Archimedes method with acetone as buoyant liquid. The thermal expansion coefficient of each zinc tellurite glasses was measured using L75D1250 dilatometer, while their glass transition temperature (Tg) was determined by the SETARAM Labsys DTA/6 differential thermogravimetric analysis at a heating rate of 20 K min−1. The acoustic Debye temperature and the softening temperature (Ts) were estimated based on the longitudinal (VL) and shear ultrasonic (Vs) wave velocities propagated in each glass sample. For ultrasonic velocity measurement of the glass sample, MATEC MBS 8000 Ultrasonic Data Acquisition System was used. All measurements were taken at 10 MHz frequency and at room temperature. All the thermal properties of such binary tellurite glasses were measured as a function of ZnO composition. The composition dependence was discussed in terms of ZnO modifiers that were expected to change the thermal properties of tellurite glasses. Experimental results show their density, and the thermal expansion coefficient increases as more ZnO content is added to the tellurite glass network, while their glass transition, Debye temperature, and the softening temperature decrease due to a change in the coordination number (CN) of the network forming atoms and the destruction of the network structure brought about by the formation of some nonbridging oxygen (NBO) atoms.

Characterization of Thermal Properties of Micro-Sized Ceramic Powders for APS Deposition of Ceramic Layers

2011 ◽  
Vol 484 ◽  
pp. 152-157 ◽  
Author(s):  
Grzegorz Moskal ◽  
Aleksander Iwaniak ◽  
Aleksandra Rozmysłowska-Grund
Keyword(s):  
Thermal Expansion ◽  
Thermal Properties ◽  
Thermal Diffusivity ◽  
Specific Heat ◽  
Thermal Expansion Coefficient ◽  
Expansion Coefficient ◽  
Pyrochlore Structure ◽  
Phase Changes ◽  
Ceramic Powders ◽  
Temperature Range

The paper presents test results concerning characteristics of the selected thermal properties of ceramic powders based on rare earth zirconates with a pyrochlore structure of RE2Zr2O7 type, intended for thermal spraying of TBCs. Gadolinium, lanthanum, samarium and neodymium based powders were tested. The scope of the tests encompassed thermal diffusivity analysis of the powders in a compressed pellets form within temperature range 25-1500°C, and also tests of specific heat and thermal expansion coefficient within similar temperature range. Standard powder of 8YSZ type on the basis of zirconium oxide modified with yttrium oxide was used as a reference material. Specific heat measurements of the powders showed that the highest values within the entire test temperature range were obtained for the standard YSZ type powder. In the case of new type of powders, the results obtained are very similar and only slightly lower in comparison with YSZ powder. The lowest values were obtained for the samarium based powder (temperature range corresponding to operating temperature). Character of the curves obtained do not show course of strong reactions connected with phase changes. Dilatometric tests of materials made it possible to determine thermal expansion coefficient. Mean coefficient values are included within the range from 5.5 x 106mm/°C to 10.0 x 106mm/°C. The highest mean value of thermal expansion coefficient was obtained for Nd2Zr2O7 powder and the lowest one for La2Zr2O7 powder. The lowest thermal diffusivity value at room temperature was shown by Nd2Zr2O7 powder, and the highest one by 8YSZ powder (0.215 mm2/s).

scholarly journals Thermal properties of polycrystalline cubic boron nitride sintered under high pressure condition

2018 ◽  
Vol 50 (4) ◽  
pp. 401-408
Author(s):  
Chunwei Leng ◽  
Xiaojun Hu ◽  
Hongliang Xie ◽  
Chunhua Shen
Keyword(s):  
Thermal Conductivity ◽  
Thermal Expansion ◽  
Thermal Properties ◽  
Boron Nitride ◽  
Thermal Expansion Coefficient ◽  
Expansion Coefficient ◽  
Bending Strength ◽  
Hexagonal Boron Nitride ◽  
Cubic Boron Nitride ◽  
Chemical Properties

The excellent thermal and chemical properties of cubic boron nitride (cBN) indicate that it is potential materials to prepare the thermal dissipate substrate applied in the electronic packaging. The thermal properties of polycrystalline cBN ceramics, however, have not been fully investigated. We report the first sintering experiment on preparing polycrystalline cBN ceramics using cBN powder as starting material without any sintering aids. The microstructure and high bending strength show that the strong combination was achieved among the crystal grains. The measured results, including density, thermal conductivity and thermal expansion coefficient, reveal that the properties of this ceramics depend on the grain size of starting crystal cBN. The PcBN ceramics has low thermal expansion coefficient extremely matching to that of silicon and exhibits moderate thermal conductivity due to its low density and the existence of low thermal conductive phase of hexagonal boron nitride.

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