Method for fabricating cermets of alumina-chromium systems

Patent · Tue Aug 09 04:00:00 EDT 1983

OSTI ID:7248406

Morgan, C S

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.

• Assignee: PTO; EDB-94-124265
• Patent Number(s): US 4397963; A
• Application Number: PPN: US 6-308738
• OSTI ID: 7248406
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360201* -- Ceramics
Cermets
& Refractories-- Preparation & Fabrication
ALLOYS
ALUMINIUM COMPOUNDS
ALUMINIUM OXIDES
CERMETS
CHALCOGENIDES
CHROMIUM ALLOYS
COMPACTING
COMPOSITE MATERIALS
DISPERSIONS
ELECTRICAL INSULATION
FABRICATION
MATERIALS
MIXTURES
OXIDES
OXYGEN COMPOUNDS
PARTICLE SIZE
SIZE
SLURRIES
SUSPENSIONS
THERMAL INSULATION
USES