High density hexagonal boron nitride prepared by hot isostatic pressing in refractory metal containers

Patent · Tue Dec 31 23:00:00 EST 1991

OSTI ID:868307

Hoenig, Clarence L ^[1]

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1. Livermore, CA

Boron nitride powder with less than or equal to the oxygen content of starting powder (down to 0.5% or less) is hot isostatically pressed in a refractory metal container to produce hexagonal boron nitride with a bulk density greater than 2.0 g/cc. The refractory metal container is formed of tantalum, niobium, tungsten, molybdenum or alloys thereof in the form of a canister or alternatively plasma sprayed or chemical vapor deposited onto a powder compact. Hot isostatic pressing at 1800.degree. C. and 30 KSI (206.8 MPa) argon pressure for four hours produces a bulk density of 2.21 g/cc. Complex shapes can be made.

• Research Organization: Lawrence Livermore National Laboratory (LLNL), Livermore, CA
• DOE Contract Number: W-7405-ENG-48
• Assignee: United States of America as represented by United States (Washington, DC)
• Patent Number(s): US 5116589
• OSTI ID: 868307
• Country of Publication: United States
• Language: English

Related Subjects

/264/423/501/
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206
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canister
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molybdenum
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oxygen
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tantalum
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