Thermal expansion of solids

Because of its low and regular thermal expansion, vitreous silica is employed in apparatus used to measure the thermal expansion of solids. A detailed account of the different methods used for this purpose has been published (227). The most common form of dilatometer utilizes a vitreous silica tube closed at the bottom and containing the test sample. A movable rod of vitreous silica, resting on the sample, actuates a dial indicator resting on the top of the rod. The assembly containing the sample is placed in a furnace, bath, or cooling chamber to attain the desired temperature. 

W. Souder, ".Thermal Expansion of Solids , USNadBurStandards Circular No 486, US-GovtPrintingOffice, Washington, DC (1950)... 

G. Ruffino, C.A. Swenson and G.K. White, 1998, Thermal expansion of solids, CINDAS Data Series on Material Properties, vol. 1-4, ed. C.Y. Ho (ASM International). 

ASTM E831, 2003. Standard test method for linear thermal expansion of solid materials by thermomechanical analysis. 

An interferometer can be used to very accurately measure the thermal expansion of solids. Although not utilized commercially to the level of dilatometry, NIST standard materials, which are in turn used to calibrate dilatometers, have had their expansion characteristics determined using interferometry. In fact, the formal definition of the meter is based on interferometric measurements. The operation of the device is based on the principle of interference of monochromatic light. The fundamental relations between wavelength and distance will first... 

S.I. Novikova. Thermal Expansion of Solids (Moscow, Nauka, 1974). 

The thermal expansion of solids depends on their structure symmetry, and may be either isotropic or anisotropic. For example, graphite has a layered structure, and its expansion in the direction perpendicular to the layers is quite different from that in the layers. For isotropic materials, ay w 3 a . However, in anisotropic solid materials the total volume expansion is distributed unequally among the three crystallographic axes and, as a rule, cannot be correctly measured by most dilatometric techniques. The true thermal expansion in such case should be studied using in situ X-ray diffraction (XRD) to determine any temperature dependence of the lattice parameters. 

ASTM E 228 Standard Test Method for Linear Thermal Expansion of Solid Materials with a Vitreous Silica Dilatometer , (Withdrawn)... 

The formula (17) finds an application in the theory of the thermal expansion of solid bodies 1 and in the theory of the band spectra of polyatomic molecules.2... 

In the limit, T = 0 K, it is known empirically that the value of the coefficient of thermal expansion of solids approaches zero as a limit. Show that, as a consequence, the entropy is independent of pressure at 0 K so that no specification of pressure is necessary in the third-law statement. 

E 228 (1995) Linear thermal expansion of solid materials with a vitreous silica dilatometer... 

COEFFICIENT OF THERMAL EXPANSION OF SOLID CYCLOHEXANE BY MEANS OF DIELECTRIC CONSTANT MEASUREMENTS. 

CRYSTAL STRUCTURE AND THERMAL EXPANSION OF SOLID METHANE. 

Thermal expansion coefficients can be measured by thermomechanical analysis (TMA). ASTM D696 describes a method of using a quartz dilatometer, and ASTM E831 describes the determination of the linear thermal expansion of solid materials. 

Implications for higJi-Tc behavior. J Phy-Cond Mat 1 SB119-SB122 Allen W, Tildesley DJ (1989) Computer Simulation of Liquids. Clarendon Press, Oxford Barron THK, Collins JG, White GK (1980) Thermal expansion of solids at low temperamres. Adv Phys 29 609-724... 

Standard Test Method for Constant-temperature Stability of Chemical Materials Standard Test Method for Arrhenius Kinetic Constants for Thermal Un.stable Materials Standard Test Method for Rapid Thermal Degradation of Solid Electrical Insulating Materials by Thermogravimetric Method Standard Test Method for Autoignition Temperature of Liquid Chemicals Standard Test Method for Specific Heat of Aircraft Turbine Lubricants by Thermal Analysis Standard Test Method for Linear Thermal Expansion of Solid Materials by Thermodilatometry... 

Determination of the thermal expansion of solids. Basic rules General rules for thermal analysis ... 

Figure 1-8 Coefficient of thermal expansion of solid solutions of p-quartz crystallized from glasses in the Si02-LiAI02 system (after Petzoldt 1967).

The principle of the thermal expansion of solids is used in bimetallic thermometers, which consist of two metal strips of different materials with different coefficients of expansion firmly connected together. Temperature differences bend these bimetallic springs and they are usually wound in spirals or coUs. The useful measuring range is from —73 to - -537°C with an accuracy of +1% of full scale [4). Bimetallic strips are used for temperature compensation in mechanical instrument movements. They are also used in switching relays to indicate whether a limiting value is exceeded. 

---