Thermal contacts between metal and glass for use at cryogenic temperatures

by Kevin O"Brien

Written in English
Published: Downloads: 75
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Edition Notes

StatementKevin O"Brien and Fred C. Witteborn.
SeriesTechnical memorandum / National Aeronautics and Space Administration -- 85856
ContributionsWitteborn, Fred C.
ID Numbers
Open LibraryOL14585696M

Milestones in the history of cryogenic technology Dewar - use of silvering and vacuum in double walled glass vessel Linde and Hampson build air liquefiers with recuperative heat exchangers Dewar - liquefies hydrogen Claude - use of piston expander Kamerlingh Onnes - liquefies helium Becquerel - freezes seeds and. Thermal Conductivity Apparatus,” Thermal Conductivity Measurements of Insulat-ing Materials at Cryogenic Temperatures, ASTM STP , FIG. 1 MLI Theoretical Heat Flow for Various Shield Emittances and Boundary Emittance C 2. The properties included are thermal conductivity, linear thermal expansion, specific heat, electrical resistivity, density, emissivity, diffusivity, and magnetic permeability. Emphasis has been given to data over a range from cryogenic (− F) to elevated temperatures ( F).Author: E. Eldridge, H. Deem.   In some metals, the thermal conductivity is a strong function of the purity and the condition of the metal. For cryogenic (cold producing) applications, copper and aluminum are used where good thermal conductivity is required. Stainless steel is used in applications where a relatively poor thermal conductivity is suitable.

Apiezon N Grease is the cryogenic Vacuum Grease of choice, it's silicone-free and specially formulated to show craze-free performance characteristics, withstanding frequent cycling between cryogenic temperatures as low as °C and +30°C. The effects of the contact pressure, the average interface temperature and the thickness of the interstitial layer are evaluated. A novel dimensionless correlation is derived from the experimental results that describes the thermal contact conductance of joints which include a soft interstitial material, at cryogenic by: This cryogenic grease is specially formulated to exhibit craze-free performance characteristics at low temperatures and withstand frequent cycling between cryogenic temperatures as low as degrees Celsius. Apiezon N Grease is a high vacuum grease which has the ability to fill the micro pores of adjoining surfaces, and improve thermal : AJVS. When designing plastic components for use in cryogenic conditions, it is generally beneficial to select plastic materials that exhibit ductile behavior at low temperatures and have low rates of thermal expansion. For cold temperature applications where heat transfer is a concern, it is also important to select a plastic material with the right.

Cryogenic Properties of Copper. Copper and copper alloys retain a high degree of ductility and toughness at subzero temperatures. In fact, copper alloys become stronger and more ductile as the temperature goes down, retaining excellent impact resistance to 20 K ( C or F). Fernico II is used at cryogenic temperatures in the °C range. Both are used to create electrically conductive paths through the walls of sealed borosilicate glass containers. Dumet is used for a similar purpose, but is tailored for seals through soda . als Properties, Thermal Expansion of Solids, Vol 1–4, ASM International, 2. “Standard Test Method for Linear Thermal Expansion of Solid Materials with a Vitreous Silica Dilatometer,” E , Annual Book of ASTM Standards,ASTM, 3. “Standard Test Method for Linear Thermal Expansion of Rigid Solids with Interferome-. fibrous material, loose of fabricated into convenient forms, mainly intended for use at appropriate elevated temperatures. The fibers may consist of silica or of an appropriate metal silicate e.g. atively, they may be formed synthetically from appropriate refractory metal oxides e.g.. alumina, zirconia.

Thermal contacts between metal and glass for use at cryogenic temperatures by Kevin O"Brien Download PDF EPUB FB2

A mechanical thermal switch is designed and fabricated to shorten the cool-down time of a conduction-cooled cryogenic system in which several copper heat loads are selected as experimental object.

Get this from a library. Thermal contacts between metal and glass for use at cryogenic temperatures. [Kevin O'Brien; Fred C Witteborn; Ames Research Center.]. Thermal contacts designed to cool a cm diam fused-silica mirror to 5 K without serious distortion of the optical surfaces were tested.

Rubber cement and copper-filled rubber cement were found to be well suited for maintaining thermal contact between the fused-silica and copper straps. Thermal resistant glass is used extensively in cryogenic experimental work.

Many others have and are using this glass in the low temperature field. Pomerantz, et al, of the National Bureau of Standards used a glass still for the separation of H 2 and HD. Germann of the University of Colorado used glass with liquid helium at Geneva Author: H.

Landay. Some measurements of thermal conductivity are described: an alloy and an almost pure metal in the 4–77 K range; a pure metal at very low temperatures; and a polymer between 80 mK and room temperature. The most common technique for the measurement of thermal conductivity at low temperatures is the “steady longitudinal flow method”: a steady thermal power flow.

New data are presented in the temperature range from 4 K to K for the thermal resistance between different metals (Cu, stainless steel), interlayered by various cryogenic bonding agents. Thermal contact resistance of solid–solid was measured by the Laser Photothermal Method. Effects on thermal contact resistance of loading pressure, temperature are analyzed.

Thermal contact resistance depends linearly on the loading pressure. Thermal contact resistance has a power relationship with the temperature.

Thermal contact resistance of SS –SS is Cited by: DEVICE FOR MEASUREMENT OF THERMAL EMISSIVITY AT CRYOGENIC TEMPERATURES Tomas Kralik, Pavel Hanzelka, Vera Musilova, Ales Srnka Institute of Scientific Instruments ASCR, KralovopolskaBrno, CZ – 64, Czech Republic email: [email protected] ABSTRACT In the described device, the thermal emissivity or absorptivity of the sample is Cited by: 3.

Plastics, resins and polymers have the disadvantage of a high thermal contraction compared to metals and superconductors, which leads in composites to a thermal mismatch upon cooling to cryogenic temperatures. Dispersion and glass-fiber Cited by: However, the thermal conductivity depends on temperature, especially in the cryogenic domain, leading to nonlinear profiles- (see Fig.

Simply put, heat is transported in solids by electrons and phonons, and the thermal conductivity is seen as the sum of both contributions:File Size: 2MB. Abstract. The high-T c superconductor current lead heat intercept connection, which is utilized as a thermal intercept to remove the Joule heat from the upper stage lead to a heat sink operating at 50 – 77 K, consists of a structure where a µm film is sandwiched between two concentric copper cylinders.

The material chosen for the insulating film is Kapton MT,* a composite film Cited by: 1. Cardiff School of Physics and Astronomy, Cardiff University, 5, The Parade, Cardiff, CF24 3YB, UK (Dated: 3rd March ) Aluminium alloys are being used increasingly in cryogenic systems.

However, cryogenic thermal conduc- tivity measurements have been made on only a few of the many types in general use. Materials properties affect the performance of cryogenic temperatures can be calculated by integrating 1 st Determine RRR of metal 2.

Compute product: RRR X B 3. Use graph to estimate incremental increase in R (or ρ). Add to base value Example: RRR =. of cryogenic thermal links; a discussion of the advantages and disadvantages of both materials for this use is given.

The use of silver is also investigated briefly. Trends in the behaviour of the conductivity of aluminium in the superconducting state (to temperatures as low as 50 mK) are also discussed.

The cryogenic range thermal switches that are currently used range from gas gap and liquid gap thermal switches that rely on convective heat transfer between two surfaces to externally actuated thermal Size: 1MB.

fracture at cryogenic temperatures • Certain materials not suited for extended use • Failure loads are typically higher, so fixturing gets larger, increases thermal mass -Load cells need to be separated from the cryogen -Automation becomes more challenging at cryogenic temperatures (i.e.

valve operation). Contact; Properties of Aluminum Alloys at Cryogenic and Elevated Temperatures Abstract: Mechanical and physical properties of aluminum and aluminum alloys change when working temperature change from cryogenic ( o C) to elevated temperatures (max. o C). These changes are not so intensive compared to another materials such as steel and.

The vacuum-sealed ceramic-to-metal and glass-to-ceramic components are designed for cryogenic applications and can withstand temperatures of up to °C with a leak rate of under 1x atm cc/s Helium; they are also suitable for use with currents of over 1, A and voltages exceeding kV.

Thermal insulation systems operating in below-ambient temperature conditions are inherently susceptible to moisture intrusion and vapor drive toward the cold side.

The subsequent effects may include condensation, icing, cracking, corrosion, and other problems. To test for thermal performance of a cold insulated pipeline under relevant conditions, we must be able to. quartz or glass rovings are used.

The use of a filler has three distinct effects: The thermal contraction can be matched to that of a metal or a composite. The thermal conductivity is increased with the concentration of the filler. The flexural-strength of the material is reduced, which affects the bond between in­.

C, and is joined to a circuit board at its inner surface. The thermal contact resistance between the chip and the board is m 2 K/W, and the board thickness and thermal conductivity are L b = 5 mm and k b = 1 W/m K, respectively.

The outer surface of the board is exposed to ambient air for which h i = 40 W/m 2 K and T∞,i 20 o Size: KB.

The rugosity creates an imperfect contact, generating a temperature drop (cf. Fig. 6) due to the local contact creating constriction of the flux lines.

Additionally, the phonon scattering at the solid–solid contact (Kapitza resistance) and the heat transfer via eventual interstitial elements increase the contact thermal by: 4.

Two part, room temperature curable epoxy system with high thermal conductivity. Serviceable from cryogenic temperatures up to +°F.

Electrically isolating. Meets NASA low outgassing specifications. Halogen free. Paste consistency. Formulated to cure at ambient temperatures. Withstands 1, hours 85°C/85% RH.

EP29LPSPAO-1 BLACK. RE: Properties at cryogenic temperatures for CF8M material MagBen (Materials) 17 Mar 17 I was just wondering how the cryogenic data were generated.

(CF8M) and (CF8) will experience a martensitic transformation at low temperature when exposing to strain at mechanical testing, will have the phase transformation even without. Find helpful customer reviews and review ratings for Thermal Properties of Solids at Room and Cryogenic Temperatures (International Cryogenics Monograph Series) at Read honest and unbiased product reviews from our users.1/5.

AbstractIn this study, cryogenic (77 K) to ambient ( K) thermal shocks are induced to investigate the material behavior and failure characteristic of a random glass-mat-reinforced thermoplastic (GMT).

The GMT has numerous advantages such as robust thermal conductivity, good mechanical strength, and good impact resistance. Hence, the GMT serves Author: Kwang-Jun Park, Jeong-Hyeon Kim, Seul-Kee Kim, Haeng-Sung Heo, Jin-Ho Bae, Jae-Myung Lee.

Thermal coefficient of expansion of building materials: Here we provide a Table of Coefficient of Thermal Expansion of Building Materials - what is the linear expansion of glass, metal, wood, masonry or plastic in response to temperature changes.

Thermal expansion is given in terms of thermal expansivity (a = 1/L (dL/dT), or more usefully for most applications, in terms of the integrated expansion (or contraction) between two temperatures.

The effect in cryogenic systems is significant; a typical value for austenitic stainless steel is 3 mm of contraction per meter between K and 4K. (ambient to K) and tensile tests at cryogenic temperatures were performed on solder joints to eval_'.atetheir structural integrity.

It was determined that low-temperature solder can be used to ensure good fin-to-tube contact for cooling-coil applications. INTRODUCT ION It has been shown (ref. 1) that the cryogenic wind-tunnel concept permitsFile Size: KB.

systems are targeted for large-scale cryogenic facilities. Space applications and particle accelerators are two fields concerned with thermal shielding of cryogenic devices. Because radiation heat transfer varies with T4, heat transfer in the range of K to 77K is dominant even for devices operating at temperatures as low as 2K.

@article{osti_, title = {Thermal contact conductance of metallic coated BiCaSrCuO superconductor/copper interfaces at cryogenic temperatures}, author = {Ochterbeck, J.M.

and Peterson, G.P. and Fletcher, L.S.}, abstractNote = {The effects of vapor deposited coatings on the thermal contact conductance of cold pressed, normal state.Hence the properties of materials must be accurately known also at cryogenic temperatures. This book provides a guide for engineers, physicists, chemists, technicians who wish to approach the field of low-temperature material properties.

The focus is on the thermal properties and a large spectrum of experimental cases is reported.Principles of Cryogenic Liberation Using Liquid Nitrogen The cryogenic liberation process uses liquid nitrogen to cool composite parts to cryogenic temperatures (down to °F [°C] if necessary) to facilitate the separation of individual components.

Because each component will have a different coefficient of thermal expansion, each component.