Thermal conductance of a pressed Al-Al contact
TL;DR: In this paper, the thermal conductance of a screw-fastened joint between two blocks made of Al-alloys was measured at helium temperatures, using simple faced contact surfaces, electropolished and gold plated samples.
About: This article is published in Cryogenics.The article was published on 1981-01-01. It has received 15 citations till now. The article focuses on the topics: Thermal contact conductance & Thermal resistance.
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TL;DR: In this article, the effects of the temperature and the contact pressure on the TCR at interfaces were analyzed and the relationship between TCR and the temperature at certain contact pressure was established, and the explanation about this phenomenon was given.
53 citations
TL;DR: In this paper, the authors present experimentally de la resistance thermique de contact de surfaces de cuivre avec un fini de surface of 0,4 micron entre 1,6 and 4,2°K for des forces de pression allant jusqu'a 670 N.
Abstract: Etude experimentale de la resistance thermique de contact de surfaces de cuivre avec un fini de surface de 0,4 micron entre 1,6 et 4,2°K pour des forces de pression allant jusqu'a 670 N. Etablissement d'une correlation
28 citations
TL;DR: In this paper, a thin plate of sapphire is used to enhance thermal resistance at mechanical contacts between cryogenic components by using a thin layer of the material. But the work is limited to the use of a single plate.
10 citations
TL;DR: In this article, an upper limit of the low-temperature specific thermal Cu-Al contact resistance of 1.3 × 10 −4 T K m 2 W −1 was found, which is less than half of the lowest specific thermal press contact resistance between two gold plated copper strips.
6 citations
TL;DR: In this article, thermal contact conductance across joints at cryogenic temperature in presence of interstitials like silicon based conductive compound, epoxy based adhesive layer and acrylate based anaerobic sealant are explored.
6 citations
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TL;DR: In this paper, an apparatus for studying heat contact at low temperatures is described, and measurements of heat transfer between various surfaces in vacuo have been made, showing that the thermal conductance is independent of the area of the surfaces and is nearly proportional to the force between them, up to forces of about 200 lb.
Abstract: An apparatus for studying heat contact at low temperatures is described. Measurements of heat transfer between various surfaces in vacuo have been made. The thermal conductance is independent of the area of the surfaces and is nearly proportional to the force between them, up to forces of about 200 lb. At helium temperatures the conductance between all the types of surfaces examined is proportional to T2, but the temperature dependence is small at nitrogen temperatures. For metal contacts the electrical conductance is extremely sensitive to the previous history of the surfaces, but the heat conductance is little dependent on this. The thermal conductance is always much greater than corresponds to the electrical conductance according to the Wiedemann‐Franz‐Lorenz law and this fact, together with the differing behavior of the two conductances under changing loads, suggests that nearly all the heat flow takes place through electrically nonconducting parts of the surface. The main results are collected togeth...
81 citations
TL;DR: In this paper, a low-temperature calorimetry system is described, which differs from the apparatus described by Berman1 mainly in the method of applying the load by a screw, and measuring it by strain gauges cemented to the cantilever.
Abstract: MECHANICAL heat switches are becoming of increasing importance in low-temperature calorimetry, and in order to study thermal contact both for this practical application and from interest in the mechanism of heat transfer, we have built the apparatus sketched in Fig. 1. This differs from the apparatus described by Berman1 mainly in the method of applying the load by a screw, and measuring it by strain gauges cemented to the cantilever.
62 citations
TL;DR: In this paper, experiments in the temperature range 0.02 to 0.2°K are described which give direct evidence for Kapitza or thermal boundary resistance between foils and a slurry of chrome alum in oil, obeying the relation 3x10-6T-3A-1°K s/erg, and an extremely small thermal resistance in threaded mechanical copper-copper joints due to heat transfer by electrons.
51 citations
TL;DR: Al is a better material for a heat switch than the usually used superconductors because of its large k(n) and large Debye temperature (reducing the lattice conductivity k(s).
Abstract: We have measured the thermal conductivity of a 0.1-mm-thick Al foil in the normal and superconducting state down to 58 mK. At this temperature, our data give a ratio for the conductivities of k(n)/k(s)=1600 T(-2). They show that Al is a better material for a heat switch than the usually used superconductors because of its large k(n) and large Debye temperature (reducing the lattice conductivity k(s)). In addition, we describe the design of a heat switch and an excellent performing demountable press-contact between Al and Cu, both gold plated, as joint to the switch.
50 citations
TL;DR: In this article, the electrical resistance of simple screw-fastened joints between two bare copper blocks and blocks with various materials interposed was measured at 4.2 K. Based upon these measurements, ways to improve the low temperature thermal conductance of such joints are indicated.
21 citations