Thermal Conductivity of Diamond Gems and CVD Diamond Films: Temperature and Isotopic Composition Dependence

1993 ◽  
pp. 32-34
Author(s):  
Y. Z. Qiu ◽  
A. Witek ◽  
D. G. Onn ◽  
W. F. Banholzer ◽  
T. R. Anthony
Keyword(s):  
Thermal Conductivity ◽  
Isotopic Composition ◽  
Composition Dependence ◽  
Diamond Films ◽  
Cvd Diamond

Thermal Conductivity Measurement of CVD Diamond Films Using a Modified Thermal Comparator Method

2000 ◽  
Vol 122 (4) ◽  
pp. 808-816 ◽  
Author(s):  
K. R. Cheruparambil ◽  
B. Farouk ◽  
J. E. Yehoda ◽  
N. A. Macken
Keyword(s):  
Heat Transfer ◽  
Thermal Conductivity ◽  
Thermal Resistance ◽  
Calibration Curve ◽  
Thermal Contact ◽  
Diamond Films ◽  
Conductivity Measurement ◽  
Cvd Diamond ◽  
Conductive Heat ◽  
Comparator Method

Results from an experimental study on the rapid measurement of thermal conductivity of chemical vapor deposited (CVD) diamond films are presented. The classical thermal comparator method has been used successfully in the past for the measurement of thermal conductivity of bulk materials having high values of thermal resistance. Using samples of known thermal conductivity, a calibration curve is prepared. With this calibration curve, the comparator can be used to determine thermal conductivity of unknown samples. We have significantly modified and extended this technique for the measurement of materials with very low thermal resistance, i.e., CVD diamond films with high thermal conductivity. In addition to the heated probe, the modified comparator employs a thermoelectric cooling element of increase conductive heat transfer through the film. The thermal conductivity measurements are sensitive to many other factors such as the thermal contact resistances, anisotropic material properties, surrounding air currents and temperature, and ambient humidity. A comprehensive numerical model was also developed to simulate the heat transfer process for the modified comparator. The simulations were used to develop a “numerical” calibration curve that agreed well with the calibration curve obtained from our measurements. The modified method has been found to successfully measure the thermal conductivity of CVD diamond films. [S0022-1481(00)00804-5]

Improvement on the Cutting Performance of CVD Diamond Coated Drills in Drilling CFRP

2012 ◽  
Vol 499 ◽  
pp. 366-371 ◽  
Author(s):  
Jian Guo Zhang ◽  
Ben Wang ◽  
Fang Hong Sun ◽  
Hang Gao
Keyword(s):  
Thermal Conductivity ◽  
Wear Resistance ◽  
Diamond Films ◽  
Chemical Vapor ◽  
Cvd Diamond ◽  
Cutting Performance ◽  
Reinforced Plastics ◽  
Coated Tool ◽  
Hot Filament

Carbon fiber reinforced plastics (CFRP) is difficult to machine because of the extremely abrasive nature of the carbon fibers and its low thermal conductivity. CVD diamond films have many excellent properties such as wonderful wear resistance, high thermal conductivity and low friction coefficient, therefore depositing diamond films on the surface of drills is thought to be an effective way to elongate the lifetime of drills and improve the cutting performance. In this study, diamond films are deposited on the WC-Co drill using hot filament chemical vapor deposition (HFCVD) method. The results of characterization by the scanning electron microscope (SEM) and Raman spectrum indicate that the fabricated CVD diamond coated drill is covered with a layer of uniform and high-purity diamond films. The cutting performance of as-fabricated CVD diamond coated drill is evaluated in dry drilling CFRP, comparing with the uncoated WC-Co drill. The results demonstrate that the CVD diamond coated drill exhibits much stronger wear resistance. Its flank wear is about 50μm after drilling 30 holes, about one-third of that of WC-Co drill. Machining quality of the exit and internal wall of drilled holes shows better surface finish obtained by coated drill, which suggests that CVD diamond coated tool has great advantages in drilling CFRP.

Surface quality and composition dependence of absolute quantum photoyield of CVD diamond films

1999 ◽  
Vol 8 (2-5) ◽  
pp. 725-731 ◽  
Author(s):  
A. Laikhtman ◽  
Y. Avigal ◽  
R. Kalish ◽  
A. Breskin ◽  
R. Chechik ◽  
...  
Keyword(s):  
Surface Quality ◽  
Composition Dependence ◽  
Diamond Films ◽  
Cvd Diamond ◽  
Absolute Quantum

Determination of thermal conductivity of CVD diamond films via photoacoustic measurements

1999 ◽  
Vol 68 (6) ◽  
pp. 663-666 ◽  
Author(s):  
A.N. Obraztsov ◽  
I.Yu. Pavlovsky ◽  
V.G. Ralchenko ◽  
H. Okushi ◽  
H. Watanabe
Keyword(s):  
Thermal Conductivity ◽  
Diamond Films ◽  
Cvd Diamond

Thermal conductivity of free-standing CVD diamond films by growing on both nuclear and growth sides

2017 ◽  
Vol 76 ◽  
pp. 9-13 ◽  
Author(s):  
Bing Dai ◽  
Jiwen Zhao ◽  
Victor Ralchenko ◽  
Andrey Khomich ◽  
Alexey Popovich ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Diamond Films ◽  
Cvd Diamond ◽  
Free Standing

Thermal conductivity of CVD diamond films: high-precision, temperature-resolved measurements

1996 ◽  
Vol 5 (6-8) ◽  
pp. 688-692 ◽  
Author(s):  
E. Wörner ◽  
C. Wild ◽  
W. Müller-Sebert ◽  
R. Locher ◽  
P. Koidl
Keyword(s):  
Thermal Conductivity ◽  
High Precision ◽  
Diamond Films ◽  
Cvd Diamond ◽  
Precision Temperature

Thermal Conductivity of CVD-Diamond Films Between 80 and 700 K

1996 ◽  
Vol 444 ◽  
Author(s):  
E. Jansen ◽  
M. Schneider ◽  
E. Obermeier
Keyword(s):  
Thermal Conductivity ◽  
Diamond Films ◽  
Cvd Diamond

Abstract

scholarly journals Isotope Effect in Thermal Conductivity of Polycrystalline CVD-Diamond: Experiment and Theory

Crystals ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 322
Author(s):  
Alexander V. Inyushkin ◽  
Alexander N. Taldenkov ◽  
Victor G. Ralchenko ◽  
Andrey P. Bolshakov ◽  
Alexander V. Khomich
Keyword(s):  
Thermal Conductivity ◽  
Chemical Vapor Deposition ◽  
Isotopic Composition ◽  
Vapor Deposition ◽  
Microwave Plasma ◽  
Chemical Vapor ◽  
Polycrystalline Diamond ◽  
Cvd Diamond ◽  
Plasma Chemical Vapor Deposition

We measured the thermal conductivity κ(T) of polycrystalline diamond with natural (natC) and isotopically enriched (12C content up to 99.96 at.%) compositions over a broad temperature T range, from 5 to 410 K. The high quality polycrystalline diamond wafers were produced by microwave plasma chemical vapor deposition in CH4-H2 mixtures. The thermal conductivity of 12C diamond along the wafer, as precisely determined using a steady-state longitudinal heat flow method, exceeds much that of the natC sample at T>60 K. The enriched sample demonstrates the value of κ(298K)=25.1±0.5 W cm−1 K−1 that is higher than the ever reported conductivity of natural and synthetic single crystalline diamonds with natural isotopic composition. A phenomenological theoretical model based on the full version of Callaway theory of thermal conductivity is developed which provides a good approximation of the experimental data. The role of different resistive scattering processes, including due to minor isotope 13C atoms, defects, and grain boundaries, is estimated from the data analysis. The model predicts about a 37% increase of thermal conductivity for impurity and dislocation free polycrystalline chemical vapor deposition (CVD)-diamond with the 12C-enriched isotopic composition at room temperature.

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