Room-temperature coefficient of thermal expansion of metals derived from the elastic constants

The HfV2–HfV2O7 composite is proposed as a material with potentially temperature-independent thermophysical properties due to the combination of anomalously increasing thermoelastic constants of HfV2 with the negative thermal expansion of HfV2O7. Based on literature data, the coexistence of both a near-zero temperature coefficient of elasticity and a coefficient of thermal expansion is suggested for a composite with a phase fraction of approximately 30 vol.% HfV2 and 70 vol.% HfV2O7. To produce HfV2–HfV2O7 composites, two synthesis pathways were investigated: (1) annealing of sputtered HfV2 films in air to form HfV2O7 oxide on the surface and (2) sputtering of HfV2O7/HfV2 bilayers. The high oxygen mobility in HfV2 is suggested to inhibit the formation of crystalline HfV2–HfV2O7 composites by annealing HfV2 in air due to oxygen-incorporation-induced amorphization of HfV2. Reducing the formation temperature of crystalline HfV2O7 from 550 °C, as obtained upon annealing, to 300 °C using reactive sputtering enables the synthesis of crystalline bilayered HfV2–HfV2O7.

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Tangguh LNG Project Statistical Young’s Modulus and Thermal Expansion Coefficient Testing of Clad Pipe Specimens

Volume 4: Pipeline and Riser Technology ◽

10.1115/omae2011-49150 ◽

2011 ◽

Author(s):

Terry Griffiths ◽

Isabel Hadley ◽

Richard Johnson ◽

Fabio Micari

Keyword(s):

Thermal Expansion ◽

Young’S Modulus ◽

Room Temperature ◽

Structural Reliability ◽

Coefficient Of Thermal Expansion ◽

Young's Modulus ◽

Linear Thermal Expansion ◽

Upheaval Buckling ◽

Analysis Of Results ◽

Mean And Variance

Material testing was undertaken on samples taken from clad pipe manufactured by JSW for the Tangguh LNG project. The test programme involved testing Young’s Modulus (E) and Coefficient of Linear Thermal Expansion (α) from room temperature to above 110° on each layer. This paper summarises testing and analysis of results which enabled mean and variance on each material property to be found. Checks were also undertaken for any correlations in properties between clad and parent layers, and between Young’s Modulus and Coefficient of Thermal Expansion. Analysis results are compared to existing industry norms and their implications for the Tangguh project UHB (Upheaval Buckling) SRA (Structural Reliability Analysis) are summarised.

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Residual Stress Determination from a Laser-Based Curvature Measurement

Thermal Spray 2000: Proceedings from the International Thermal Spray Conference ◽

10.31399/asm.cp.itsc2000p0363 ◽

2000 ◽

Author(s):

W.D. Swank ◽

R.A. Gavalya ◽

J.K. Wright ◽

R.N. Wright

Keyword(s):

Residual Stress ◽

Thermal Expansion ◽

Bond Coat ◽

Room Temperature ◽

Coefficient Of Thermal Expansion ◽

Substrate Material ◽

304 Stainless Steel ◽

Cte Mismatch ◽

Mismatch Stress ◽

Sprayed Coating

Abstract Thermally sprayed coating characteristics and mechanical properties are in part a result of the residual stress developed during the fabrication process. The total stress state in a coating/substrate is comprised of the quench stress and the coefficient of thermal expansion (CTE) mismatch stress. The quench stress is developed when molten particles impact the substrate and rapidly cool and solidify. The CTE mismatch stress results from a large difference in the thermal expansion coefficients of the coating and substrate material. It comes into effect when the substrate/coating combination cools from the equilibrated deposit temperature to room temperature. This paper describes a laser-based technique for measuring the curvature of a coated substrate and the analysis required to determine residual stress from curvature measurements. Quench stresses were determined by heating the specimen back to the deposit temperature thus removing the CTE mismatch stress. By subtracting the quench stress from the total residual stress at room temperature, the CTE mismatch stress was estimated. Residual stress measurements for thick (>1mm) spinel coatings with a Ni-Al bond coat on 304 stainless steel substrates were made. It was determined that a significant portion of the residual stress results from the quenching stress of the bond coat and that the spinel coating produces a larger CTE mismatch stress than quench stress.

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The Influence of Microstructure, Heat-Treatment and Type of Crystal Lattice of Iron Aluminides on Coefficient of Thermal Expansion

Defect and Diffusion Forum ◽

10.4028/www.scientific.net/ddf.368.41 ◽

2016 ◽

Vol 368 ◽

pp. 41-44 ◽

Cited By ~ 1

Author(s):

Martin Švec

Keyword(s):

Phase Transition ◽

Heat Treatment ◽

Thermal Expansion ◽

High Temperature ◽

Room Temperature ◽

Coefficient Of Thermal Expansion ◽

Iron Aluminides ◽

Sharp Drop ◽

Structural Application ◽

Phase Transition Temperatures

The iron aluminides seem to be very perspective materials for high temperature structural application. They have many advantages, but unfortunately also some negative properties – e.g. sharp drop in strength above 600°C or limited ductility at room temperature. These disadvantages can be reduced by alloying of binary alloy by other elements.Present work deals with a study of coefficient of thermal expansion (CTE). It was investigated the influence of microstructure and heat-treatment on the values of CTE. Secondary, it was studied the possibilities, how to determine phase transition temperatures from CTE curves. Influence of type of iron aluminides lattice on CTE values was also examined as well as the influence of addition of alloying elements into binary iron aluminides.

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Thermal expansion and atomic displacement parameters of cubic KMgF3perovskite determined by high-resolution neutron powder diffraction

Journal of Applied Crystallography ◽

10.1107/s0021889802002273 ◽

2002 ◽

Vol 35 (3) ◽

pp. 291-295 ◽

Cited By ~ 43

Author(s):

I. G. Wood ◽

K. S. Knight ◽

G. D. Price ◽

J. A. Stuart

Keyword(s):

Thermal Expansion ◽

High Resolution ◽

Powder Diffraction ◽

Room Temperature ◽

Coefficient Of Thermal Expansion ◽

Atomic Displacement ◽

Debye Model ◽

Neutron Powder Diffraction ◽

First Derivative ◽

Atomic Displacement Parameters

The structure of KMgF3has been determined by high-resolution neutron powder diffraction at 4.2 K, room temperature and at 10 K intervals from 373 K to 1223 K. The material remains cubic at all temperatures. The average volumetric coefficient of thermal expansion in the range 373–1223 K was found to be 7.11 (3) × 10−5 K−1. For temperatures between 4.2 and 1223 K, a second-order Grüneisen approximation to the zero-pressure equation of state, with the internal energy calculatedviaa Debye model, was found to fit well, with the following parameters: θD= 536 (9) K,Vo= 62.876 (6) Å3, K_{o}^{\,\prime} = 6.5 (1) and (VoKo/γ′) = 3.40 (2) × 10−18 J, where θDis the Debye temperature,Vois the volume atT= 0, K_{o}^{\,\prime} is the first derivative with respect to pressure of the incompressibility (Ko) and γ′ is a Grüneisen parameter. The atomic displacement parameters were found to increase smoothly withTand could be fitted using Debye models with θDin the range 305–581 K. At 1223 K, the displacement of the F ions was found to be much less anisotropic than that in NaMgF3at this temperature.

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The Linear Coefficient of Thermal Expansion of Silicon at Room Temperature

Powder Diffraction ◽

10.1017/s0885715600017292 ◽

1991 ◽

Vol 6 (3) ◽

pp. 147-152 ◽

Cited By ~ 5

Author(s):

Liu Fengchao ◽

Zheng Bin

Keyword(s):

Thermal Expansion ◽

Single Crystal ◽

Room Temperature ◽

Coefficient Of Thermal Expansion ◽

Silicon Single Crystal ◽

Linear Coefficient ◽

X Ray ◽

Crystal State ◽

Powder Diffractometer ◽

Powder Samples

AbstractThe linear coefficient of thermal expansion for three silicon single-crystal samples, taken from the head, middle, and tail of the same boule, and their powder samples have been measured at room temperature by using an X-ray powder diffractometer. All samples yield the same expansion value α=2.45 (± 0.04) × 10−6 °C at 25 °C. The results of this experiment show that the linear coefficient of thermal expansion of silicon at room temperature is not dependent on its single-crystal state or its powder state.

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The Structure, Vibrational Spectra, and Thermal Expansion Study of AVO4 (A=Bi, Fe, Cr) and Co2V2O7

Materials ◽

10.3390/ma13071628 ◽

2020 ◽

Vol 13 (7) ◽

pp. 1628 ◽

Cited By ~ 3

Author(s):

Xiaoke He ◽

Chenjun Zhang ◽

Ding Tian

Keyword(s):

Thermal Expansion ◽

Room Temperature ◽

Coefficient Of Thermal Expansion ◽

Linear Thermal Expansion ◽

Monoclinic Structure ◽

Functional Material ◽

Temperature Dependent ◽

Vanadium Compounds ◽

Measurement Results ◽

Thermal Expansion Study

Vanadate is an important functional material. It has been widely studied and applied in luminescence and photocatalysis. Vanadium compounds have been synthesized to investigate the thermal expansion properties and structure. Both BiVO4 and Co2V2O7 are monoclinic at room temperature, FeVO4’s crystal structure is triclinic, and CrVO4 is orthorhombic. The relatively linear, thermal-expansion, and temperature-dependent Raman spectroscopy results showed that the phase transition of BiVO4 occurred at 200 to 300 °C. The coefficient of thermal expansion (CTE) of Co2V2O7 was larger than that of the monoclinic structure BiVO4. The CTE of the tetragonal structure of BiVO4 was 15.27 × 10−6 °C−1 which was the largest CTE in our measurement results, and the CTE of anorthic structure FeVO4 was 2.84 × 10−6 °C−1 and was the smallest.

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Crystal structure, dielectric, piezoelectric and elastic properties of (±)-tris(ethylenediamine)cobalt(III) nitrate, (±)–[Co(H2N(CH2)2NH2)3](NO3)3

Zeitschrift für Kristallographie - Crystalline Materials ◽

10.1524/zkri.1998.213.3.161 ◽

1998 ◽

Vol 213 (3) ◽

Cited By ~ 1

Author(s):

S. Haussühl ◽

J. Schreuer

Keyword(s):

Crystal Structure ◽

Thermal Expansion ◽

Single Crystals ◽

Elastic Properties ◽

Structure Analysis ◽

Elastic Constants ◽

Room Temperature ◽

Optical Quality ◽

X Ray

AbstractLarge single crystals of optical quality of (±)-tris(ethylenediamine)cobalt(III) nitrate have been grown from aequeous solutions. An X-ray structure analysis yielded space groupPyroelectric, dieletric, piezoelectric and elastic constants have been determined at room temperature. Additionally, we have studied the coefficients of thermal expansion and the thermoelastic constants in the range between 270 K and 350 K. The structure exhibits a nearly trigonal symmetry around the [unk]

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