The effect of surface bond reconstruction of thermal contact surfaces on phonon transport in atomic wire

2009 ◽  
Vol 106 (5) ◽  
pp. 054312 ◽  
Author(s):  
Jing Li ◽  
T. C. Au Yeung ◽  
C. H. Kam ◽  
Xuean Zhao ◽  
Qing-Hu Chen ◽  
...  
Keyword(s):  
Thermal Contact ◽  
Phonon Transport ◽  
Contact Surfaces ◽  
Surface Bond ◽  
Effect Of Surface

Anharmonic phonon transport in atomic wire coupled by thermal contacts with surface bond reconstruction

2009 ◽  
Vol 106 (1) ◽  
pp. 014308 ◽  
Author(s):  
Jing Li ◽  
T. C. Au Yeung ◽  
C. H. Kam ◽  
Yue Peng ◽  
Qing-hu Chen ◽  
...  
Keyword(s):  
Phonon Transport ◽  
Thermal Contacts ◽  
Surface Bond

Four-Probe Measurement of Thermal Transport in Suspended Few-Layer Graphene With Polymer Residue

2019 ◽  
Vol 141 (6) ◽  
Author(s):  
Eric Ou ◽  
Xun Li ◽  
Sangyeop Lee ◽  
Kenji Watanabe ◽  
Takashi Taniguchi ◽  
...  
Keyword(s):  
Thermal Resistance ◽  
Thermal Transport ◽  
Thermal Contact ◽  
Experimental Studies ◽  
Phonon Transport ◽  
Contact Thermal Resistance ◽  
Layer Graphene ◽  
Scattering Rate ◽  
Transport Measurements ◽  
Polymeric Residue

The presence of unknown thermal contact thermal resistance has limited prior two-probe thermal transport measurements of suspended graphene samples. Here, we report four-probe thermal transport measurements of suspended seven-layer graphene. By isolating the thermal contact resistance, we are able to attribute the observed reduced thermal conductivity primarily to polymeric residue on the sample instead of the contact thermal resistance, which resulted in ambiguity in the prior experimental studies of the effect of polymer reside. The extrinsic scattering rate due to the polymer residue is extracted from the measurement results based on a solution of the Peierls-Boltzmann phonon transport equation.

Analysis of heat transfer between solids at low temperatures

1976 ◽  
Vol 54 (17) ◽  
pp. 1749-1771 ◽  
Author(s):  
J. D. N. Cheeke ◽  
H. Ettinger ◽  
B. Hebral
Keyword(s):  
Heat Transfer ◽  
Thermal Contact ◽  
Impedance Matching ◽  
Debye Model ◽  
Phonon Transport ◽  
Transfer Coefficients ◽  
Heat Transfer Coefficients ◽  
Critical Cone ◽  
Acoustic Mismatch ◽  
The Heat Transfer Coefficient

A detailed analysis is given of the acoustic mismatch formulation first given by Little for the thermal contact resistance between solids for the case of phonon transport in a Debye model. Extrema in the heat transfer coefficients as a function of the refractive index of the interface are shown to be due to either impedance matching conditions or to the presence of the critical cone. Detailed numerical tables are presented which permit rapid evaluation of the heat transfer coefficient to an accuracy of 5% or better.

Effect of surface bond-order loss on the electronic thermal conductivity of metallic polycrystalline films

2005 ◽  
Vol 98 (11) ◽  
pp. 113707 ◽  
Author(s):  
T. C. Au Yeung ◽  
T. C. Chiam ◽  
Chang Q. Sun ◽  
Mingxia Gu ◽  
W. Z. Shangguan ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Bond Order ◽  
Polycrystalline Films ◽  
Electronic Thermal Conductivity ◽  
Surface Bond ◽  
Effect Of Surface

Effect of Surface Texturing on EHD Lubrication Films Under Transient Speed Condition

2011 ◽  
Author(s):  
Martin Zimmerman ◽  
Ivan Krupka ◽  
Martin Hartl ◽  
Pavel Houska
Keyword(s):  
Film Thickness ◽  
Flat Surface ◽  
Contact Point ◽  
Surface Texturing ◽  
Polished Surface ◽  
Speed Profile ◽  
Ehd Lubrication ◽  
Machine Elements ◽  
Contact Surfaces ◽  
Effect Of Surface

Transient EHD lubrication, where operating parameters such as speed, load and surface curvature vary over time, occurs in many machine elements such as cams, gears or roller bearings. The effect of transient speed and surface texturing on EHD lubrication films are investigated by the direct observation. For the purposes of the experiment the speed profile of contact point between cam and follower is used. Most critical part of the operation is when the contact surfaces are running in opposite directions. This effect can cause a lubricant film breakdown and in consequence also damage of contact surfaces. For this reason three types of experiments, for the same speed profile, are carried out for polished surface and for contact surfaces with and without surface texturing. It has enabled us to consider if the texture of micro-dents have any significant influence on film thickness especially in critical parts of the operation. To simplify the problem the concept of cam and follower contact was replaced by EHD contact of the flat surface of chromium coated glass disk and a steel ball. Also only transient speed was taken into account. The method used to measured film thickness was thin film colorimetric interferometry. The experimental results show that micro-dents could increase lubrication efficiency under rolling/sliding condition through the lubricant emitted from micro-dents. It was found that the lubricant emitted from micro-dents helps to separate contact surfaces especially in the case where the contact surfaces moves very slowly in the opposite direction.

Influence of Flatness and Waviness of Rough Surfaces on Surface Contact Conductance

2003 ◽  
Vol 125 (3) ◽  
pp. 394-402 ◽  
Author(s):  
S. Sunil Kumar ◽  
K. Ramamurthi
Keyword(s):  
Surface Roughness ◽  
Material Properties ◽  
Thermal Contact ◽  
Thermal Contact Conductance ◽  
Threshold Values ◽  
Average Roughness ◽  
Contact Conductance ◽  
Surface Parameters ◽  
Wavy Surfaces ◽  
Effect Of Surface

The effect of surface roughness, waviness and flatness deviations on thermal contact conductance is predicted. Threshold values of the surface parameters which do not adversely influence thermal contact conductance are determined. Flatness deviations less than ten times the average roughness and waviness less than about four times the average roughness do not significantly affect the contact conductance. A correlation is developed for contact conductance in terms of the surface parameters, the material properties and the contact pressure at the joint. Experiments are conducted in vacuum with rough, non-flat and wavy surfaces and the experimental results are demonstrated to agree well with the predictions.

Sign in / Sign up

Export Citation Format

Share Document