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Title: Chemical vapor deposited diamond-on-diamond powder composites (LDRD final report)

Abstract

Densifying non-mined diamond powder precursors with diamond produced by chemical vapor infiltration (CVI) is an attractive approach for forming thick diamond deposits that avoids many potential manufacturability problems associated with predominantly chemical vapor deposition (CVD) processes. The authors developed techniques for forming diamond powder precursors and densified these precursors in a hot filament-assisted reactor and a microwave plasma-assisted reactor. Densification conditions were varied following a fractional factorial statistical design. A number of conclusions can be drawn as a result of this study. High density diamond powder green bodies that contain a mixture of particle sizes solidify more readily than more porous diamond powder green bodies with narrow distributions of particle sizes. No composite was completely densified although all of the deposits were densified to some degree. The hot filament-assisted reactor deposited more material below the exterior surface, in the interior of the powder deposits; in contrast, the microwave-assisted reactor tended to deposit a CVD diamond skin over the top of the powder precursors which inhibited vapor phase diamond growth in the interior of the powder deposits. There were subtle variations in diamond quality as a function of the CVI process parameters. Diamond and glassy carbon tended to form at themore » exterior surface of the composites directly exposed to either the hot filament or the microwave plasma. However, in the interior, e.g. the powder/substrate interface, diamond plus diamond-like-carbon formed. All of the diamond composites produced were grey and relatively opaque because they contained flawed diamond, diamond-like-carbon and glassy carbon. A large amount of flawed and non-diamond material could be removed by post-CVI oxygen heat treatments. Heat treatments in oxygen changed the color of the composites to white.« less

Authors:
; ; ; ; ;
Publication Date:
Research Org.:
Sandia National Labs., Albuquerque, NM (United States)
Sponsoring Org.:
USDOE, Washington, DC (United States)
OSTI Identifier:
206565
Report Number(s):
SAND-95-2105
ON: DE96006442; TRN: AHC29607%%84
DOE Contract Number:  
AC04-94AL85000
Resource Type:
Technical Report
Resource Relation:
Other Information: PBD: Dec 1995
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; COMPOSITE MATERIALS; CHEMICAL VAPOR DEPOSITION; DIAMONDS; CHEMICAL REACTORS; SOLIDIFICATION; IMPREGNATION; EXPERIMENTAL DATA; SCANNING ELECTRON MICROSCOPY; MICROSTRUCTURE; RAMAN SPECTROSCOPY

Citation Formats

Panitz, J K, Hsu, W L, Tallant, D R, McMaster, M, Fox, C, and Staley, D. Chemical vapor deposited diamond-on-diamond powder composites (LDRD final report). United States: N. p., 1995. Web. doi:10.2172/206565.
Panitz, J K, Hsu, W L, Tallant, D R, McMaster, M, Fox, C, & Staley, D. Chemical vapor deposited diamond-on-diamond powder composites (LDRD final report). United States. https://doi.org/10.2172/206565
Panitz, J K, Hsu, W L, Tallant, D R, McMaster, M, Fox, C, and Staley, D. Fri . "Chemical vapor deposited diamond-on-diamond powder composites (LDRD final report)". United States. https://doi.org/10.2172/206565. https://www.osti.gov/servlets/purl/206565.
@article{osti_206565,
title = {Chemical vapor deposited diamond-on-diamond powder composites (LDRD final report)},
author = {Panitz, J K and Hsu, W L and Tallant, D R and McMaster, M and Fox, C and Staley, D},
abstractNote = {Densifying non-mined diamond powder precursors with diamond produced by chemical vapor infiltration (CVI) is an attractive approach for forming thick diamond deposits that avoids many potential manufacturability problems associated with predominantly chemical vapor deposition (CVD) processes. The authors developed techniques for forming diamond powder precursors and densified these precursors in a hot filament-assisted reactor and a microwave plasma-assisted reactor. Densification conditions were varied following a fractional factorial statistical design. A number of conclusions can be drawn as a result of this study. High density diamond powder green bodies that contain a mixture of particle sizes solidify more readily than more porous diamond powder green bodies with narrow distributions of particle sizes. No composite was completely densified although all of the deposits were densified to some degree. The hot filament-assisted reactor deposited more material below the exterior surface, in the interior of the powder deposits; in contrast, the microwave-assisted reactor tended to deposit a CVD diamond skin over the top of the powder precursors which inhibited vapor phase diamond growth in the interior of the powder deposits. There were subtle variations in diamond quality as a function of the CVI process parameters. Diamond and glassy carbon tended to form at the exterior surface of the composites directly exposed to either the hot filament or the microwave plasma. However, in the interior, e.g. the powder/substrate interface, diamond plus diamond-like-carbon formed. All of the diamond composites produced were grey and relatively opaque because they contained flawed diamond, diamond-like-carbon and glassy carbon. A large amount of flawed and non-diamond material could be removed by post-CVI oxygen heat treatments. Heat treatments in oxygen changed the color of the composites to white.},
doi = {10.2172/206565},
url = {https://www.osti.gov/biblio/206565}, journal = {},
number = ,
volume = ,
place = {United States},
year = {1995},
month = {12}
}