Method for fabricating cermets of alumina-chromium systems

Patent · Sat Jan 01 00:00:00 EST 1983

OSTI ID:864656

Morgan, Chester S ^[1]

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1. Oak Ridge, TN

Cermet insulators resistant to thermal and mechanical shock are prepared from alumina-chromium systems by providing an Al.sub.2 O.sub.3 material of about 0.5 to 7.0 micron size with a solid-hydrocarbon overcoating by slurring an effective amount of said solid hydrocarbon in a solvent mixture containing said Al.sub.2 O.sub.3 and thereafter evaporating said solvent, contacting said coated Al.sub.2 O.sub.3 with a solution of chromium precursor compound, heating the resulting mixture in a reducing environment to a temperature above the decomposition temperature of said chromium precursor compound but less than the melting temperature of the Al.sub.2 O.sub.3 or chromium for sufficient duration to yield a particulate compound having chromium essentially dispersed throughout the Al.sub.2 O.sub.3, and then densifying said particulate to provide said cermet characterized by a theoretical density in excess of 96% and having 0.1 to 10.0 vol.% elemental chromium metal present therein as a dispersed phase at the boundaries of the Al.sub.2 O.sub.3 material. Cermet components prepared thereby are useful in high temperature equipment, advanced heat engines, and nuclear-related equipment applications where electrical or thermal insulators are required.

• Research Organization: Oak Ridge National Laboratory (ORNL), Oak Ridge, TN (United States)
• Assignee: Morgan, Chester S. (Oak Ridge, TN)
• Patent Number(s): US 4397963
• OSTI ID: 864656
• Country of Publication: United States
• Language: English

Related Subjects

method
fabricating
cermets
alumina-chromium
systems
cermet
insulators
resistant
thermal
mechanical
shock
prepared
providing
material
micron
size
solid-hydrocarbon
overcoating
slurring
effective
amount
solid
hydrocarbon
solvent
mixture
containing
thereafter
evaporating
contacting
coated
solution
chromium
precursor
compound
heating
resulting
reducing
environment
temperature
decomposition
melting
sufficient
duration
yield
particulate
essentially
dispersed
throughout
densifying
provide
characterized
theoretical
density
excess
96
10
vol
elemental
metal
therein
phase
boundaries
components
useful
equipment
advanced
heat
engines
nuclear-related
applications
electrical
required
heat engines
dispersed throughout
theoretical density
resulting mixture
melting temperature
effective amount
heat engine
mixture containing
dispersed phase
decomposition temperature
solvent mixture
thermal insulator
reducing environment
mechanical shock
solid hydrocarbon
micron size
sufficient duration
precursor compound
components prepared
cermet insulators
cermet insulator
alumina-chromium systems
/501/75/