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Title: Method for removing oxide contamination from silicon carbide powders

Abstract

The described invention is directed to a method for removing oxide contamination in the form of oxygen-containing compounds such as SiO/sub 2/ and B/sub 2/O/sub 3/ from a charge of finely divided silicon carbide. The silicon carbide charge is contacted with a stream of hydrogen fluoride mixed with an inert gas carrier such as argon at a temperature in the range of about 200/sup 0/ to 650/sup 0/C. The oxides in the charge react with the heated hydrogen fluoride to form volatile gaseous fluorides such as SiF/sub 4/ and BF/sub 3/ which pass through the charge along with unreacted hydrogen fluoride and the carrier gas. Any residual gaseous reaction products and hydrogen fluoride remaining in the charge are removed by contacting the charge with the stream of inert gas which also cools the powder to room temperature. The removal of the oxygen contamination by practicing the present method provides silicon carbide powders with desirable pressing and sintering characteristics. 1 tab.

Inventors:
;
Publication Date:
Research Org.:
Oak Ridge National Lab., TN (USA)
OSTI Identifier:
5786688
Application Number:
ON: DE85011648
Assignee:
Dept. of Energy EDB-85-095791
DOE Contract Number:  
AC05-84OR21400
Resource Type:
Patent
Country of Publication:
United States
Language:
English
Subject:
37 INORGANIC, ORGANIC, PHYSICAL AND ANALYTICAL CHEMISTRY; 36 MATERIALS SCIENCE; BORON OXIDES; REMOVAL; SILICA; SILICON CARBIDES; PURIFICATION; CHEMICAL REACTIONS; HIGH TEMPERATURE; HYDROFLUORIC ACID; PRESSING; REFRACTORIES; SINTERED MATERIALS; BORON COMPOUNDS; CARBIDES; CARBON COMPOUNDS; CHALCOGENIDES; FABRICATION; HYDROGEN COMPOUNDS; INORGANIC ACIDS; MATERIALS; MATERIALS WORKING; MINERALS; OXIDE MINERALS; OXIDES; OXYGEN COMPOUNDS; SILICON COMPOUNDS; SILICON OXIDES; 400201* - Chemical & Physicochemical Properties; 360201 - Ceramics, Cermets, & Refractories- Preparation & Fabrication

Citation Formats

Brynestad, J., and Bamberger, C.E. Method for removing oxide contamination from silicon carbide powders. United States: N. p., 1984. Web.
Brynestad, J., & Bamberger, C.E. Method for removing oxide contamination from silicon carbide powders. United States.
Brynestad, J., and Bamberger, C.E. Wed . "Method for removing oxide contamination from silicon carbide powders". United States.
@article{osti_5786688,
title = {Method for removing oxide contamination from silicon carbide powders},
author = {Brynestad, J. and Bamberger, C.E.},
abstractNote = {The described invention is directed to a method for removing oxide contamination in the form of oxygen-containing compounds such as SiO/sub 2/ and B/sub 2/O/sub 3/ from a charge of finely divided silicon carbide. The silicon carbide charge is contacted with a stream of hydrogen fluoride mixed with an inert gas carrier such as argon at a temperature in the range of about 200/sup 0/ to 650/sup 0/C. The oxides in the charge react with the heated hydrogen fluoride to form volatile gaseous fluorides such as SiF/sub 4/ and BF/sub 3/ which pass through the charge along with unreacted hydrogen fluoride and the carrier gas. Any residual gaseous reaction products and hydrogen fluoride remaining in the charge are removed by contacting the charge with the stream of inert gas which also cools the powder to room temperature. The removal of the oxygen contamination by practicing the present method provides silicon carbide powders with desirable pressing and sintering characteristics. 1 tab.},
doi = {},
journal = {},
number = ,
volume = ,
place = {United States},
year = {1984},
month = {8}
}