Method for fabricating cermets of alumina-chromium systems

Patent · Fri Dec 31 23:00:00 EST 1982

OSTI ID:864656

Morgan, Chester S ^[1]

---

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

Related Subjects

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