Coated graphite articles useful in metallurgical processes and method for making same
- Knoxville, TN
Graphite articles including crucibles and molds used in metallurgical processes involving the melting and the handling of molten metals and alloys that are reactive with carbon when in a molten state and at process temperatures up to about 2000.degree. C. are provided with a multiple-layer coating for inhibiting carbon diffusion from the graphite into the molten metal or alloys. The coating is provided by a first coating increment of a carbide-forming metal on selected surfaces of the graphite, a second coating increment of a carbide forming metal and a refractory metal oxide, and a third coating increment of a refractory metal oxide. The second coating increment provides thermal shock absorbing characteristics to prevent delamination of the coating during temperature cycling. A wash coat of unstabilized zirconia or titanium nitride can be applied onto the third coating increment to facilitate release of melts from the coating.
- Research Organization:
- Oak Ridge National Laboratory (ORNL), Oak Ridge, TN (United States)
- Assignee:
- Martin Marietta Energy Systems, Inc. (Oak Ridge, TN)
- Patent Number(s):
- US 5443892
- OSTI ID:
- 870040
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
graphite
articles
useful
metallurgical
processes
method
including
crucibles
molds
involving
melting
handling
molten
metals
alloys
reactive
carbon
process
temperatures
2000
degree
provided
multiple-layer
coating
inhibiting
diffusion
metal
increment
carbide-forming
selected
surfaces
carbide
forming
refractory
oxide
third
provides
thermal
shock
absorbing
characteristics
prevent
delamination
temperature
cycling
wash
coat
unstabilized
zirconia
titanium
nitride
applied
facilitate
release
melts
molten metals
selected surface
forming metal
thermal shock
titanium nitride
refractory metal
molten metal
metal oxide
stabilized zirconia
metallurgical process
articles including
carbide forming
processes involving
graphite articles
prevent delamination
metallurgical processes
temperature cycling
coated graphite
articles useful
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