Thermal Contact Conductance of Metallic Coated BiCaSrCuO Superconductor/Copper Interfaces at Cryogenic Temperatures

1992 ◽  
Vol 114 (1) ◽  
pp. 21-29 ◽  
Author(s):  
J. M. Ochterbeck ◽  
G. P. Peterson ◽  
L. S. Fletcher
Keyword(s):  
Vapor Deposition ◽  
Thermal Contact ◽  
Deposition Process ◽  
Thermal Contact Conductance ◽  
Experimental Program ◽  
Contact Conductance ◽  
Nickel Substrates ◽  
Deposition Processes ◽  
Cold Pressed ◽  
And Control

The effects of vapor deposited coatings on the thermal contact conductance of cold pressed, normal state BiCaSrCuO superconductor/oxygen-free copper interfaces were experimentally investigated over a pressure range of 200 to 2000 kPa. Using traditional vapor deposition processes, thin coatings of indium or lead were applied to the superconductor material to determine the effect on the heat transfer occurring at the interface. The test data indicate that the contact conductance can be enhanced using these coatings, with indium providing the greater enhancement. The experimental program revealed the need for a better understanding and control of the vapor deposition process when using soft metallic coatings. Also, the temperature-dependent microhardness of copper was experimentally determined and found to increase by approximately 35 percent as the temperature decreased from 300 to 85 K. An empirical model was developed to predict the effect of soft coatings on the thermal contact conductance of the superconductor/copper interfaces. When applied, the model agreed well with the data obtained in this investigation at low coating thicknesses but overpredicted the data as the thickness increased. In addition, the model agreed very well with data obtained in a previous investigation for silver-coated nickel substrates at all coating thicknesses.

Effects of Metallic Vapor Deposition Process and the Overall Coating Thickness on Thermal Contact Conductance

1995 ◽  
Vol 117 (4) ◽  
pp. 828-834 ◽  
Author(s):  
A. H. Howard ◽  
J. M. Ochterbeck ◽  
G. P. Peterson
Keyword(s):  
Coating Thickness ◽  
Vapor Deposition ◽  
Thermal Contact ◽  
Deposition Process ◽  
Thermal Contact Conductance ◽  
Maximum Enhancement ◽  
Test Set ◽  
Contact Conductance ◽  
Layered Coatings ◽  
Vapor Deposition Process

An investigation was conducted to determine the effects of the vapor deposition process and. the interstitial coating thickness on the overall joint conductance of metallic interfaces. Eight aluminum 6061-T6 test specimens were coated with indium and tested while in contact with uncoated aluminum 6061-T6 specimens. In the first test set, all specimens were coated to a thickness of 3.51 μm, but the vapor deposition process was varied to produce both single and multiple-layered coated specimens. In the second test set, the coating thickness was varied from 0.026 μm to 3.51 μm. The results indicated that when creating multiple layered coatings, oxidation and thermal cycling caused poor layer adhesion, and resulted in significantly reduced dimensionless contact conductance enhancement factors than for single-layered coatings with an equivalent thickness. Additionally, the results demonstrated that the thermal contact conductance could be enhanced to much greater levels than previously reported in the literature, and that the dimensionless enhancement factor asymptotically approached a maximum enhancement value. A theoretical maximum enhancement limit has been presented for comparison with the experimental data.

A New Method for Measuring Thermal Contact Conductance—Experimental Technique and Results

2011 ◽  
Vol 133 (7) ◽  
Author(s):  
Simon Woodland ◽  
Andrew D. Crocombe ◽  
John W. Chew ◽  
Stephen J. Mills
Keyword(s):  
Thermal Contact ◽  
New Method ◽  
Thermal Contact Conductance ◽  
Experimental Program ◽  
Material Strength ◽  
Metal Working ◽  
Test Rig ◽  
Contact Conductance ◽  
Material Parameters ◽  
Pressure Surface

Thermal contact conductance (TCC) is used to characterize heat transfer across interfaces in contact. It is important in thermal modeling of turbomachinery components and finds many other applications in the aerospace, microelectronic, automotive and metal working industries. In this paper, a new method for measuring TCC is described and demonstrated. A test rig is formed from an instrumented split tube with in-line washers and loading applied under controlled conditions. The experimental method and data analysis are described, and the effects on thermal contact conductance of important parameters such as the contact pressure, surface roughness, temperature, thermal conductivity, and material strength are investigated. Normalization of the TCC measured in the experimental program was carried out using appropriate surface and material parameters. The results of this normalization are used to compare the normalized experimental results with various models from the literature.

Review of models for thermal contact conductance of metals

10.2514/3.870 ◽  
1997 ◽  
Vol 11 ◽  
pp. 129-140
Author(s):  
B. Merci ◽  
J. Steelant ◽  
J. Vierendeels ◽  
K. Riemslagh ◽  
E. Dick ◽  
...  
Keyword(s):  
Thermal Contact ◽  
Thermal Contact Conductance ◽  
Contact Conductance

Thermal contact conductance of adhesives for microelectronic systems

10.2514/3.871 ◽  
1997 ◽  
Vol 11 ◽  
pp. 141-145
Author(s):  
Andreas Haselbacher ◽  
Jiri Blazek ◽  
S. R. Mirmira ◽  
E. Marotta ◽  
L. S. Fletcher
Keyword(s):  
Thermal Contact ◽  
Thermal Contact Conductance ◽  
Contact Conductance
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