Refractory, electrically conductive, mixed materials containing boron nitride and process for their manufacture
The invention is refractory, electrically conductive, mixed materials based on hexagonal boron nitride and at least one electrically conductive component such as titanium boride and zirconium boride, and having a density of at leadt about 95% of the theoretical density and nondirection-dependent properties, which have been manufactured from powder mixtures that are practically free of oxygen and metal and comprise from about 10 to 60% by weight of boron nitride, from about 0 to 60% by weight of aluminum nitride and/or silicon nitride, and from about 30 to 70% by weight of an electrically conductive component, without the concomitant use of sintering aids by means of isostatic hot pressing in a vacuum-tight casing at temperatures of from about 1400/sup 0/ to 1700/sup 0/ C. and under a pressure of from about 100 to 300 MPa. The powder mixtures are pre-densified to form green bodies in block form and are then introduced into casings or coated with a material forming a vacuum-tight casing. The pre-densified green bodies in the vacuum-tight casing are then subjected to the isostatic hot-pressing process in a high-pressure autoclave, using an inert gas such as argon, as pressure-transmission medium. The article formed from the mixed materials are used to manufacture evaporation boats for the vacuum evaporation of metals.
- Assignee:
- Elektroschmelzwerk Kempten GmbH (Germany, Federal Republic Of)
- Patent Number(s):
- US 4528120
- OSTI ID:
- 6466754
- Resource Relation:
- Patent Priority Date: Priority date 19 Apr 1984, Germany, Federal Republic of (F.R. Germany); Other Information: PAT-APPL-601986
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
REFRACTORIES
CHEMICAL COMPOSITION
CHEMICAL PREPARATION
ELECTRIC CONDUCTIVITY
PRESSING
ARGON
AUTOCLAVES
BORON NITRIDES
COMPRESSION
CONTROLLED ATMOSPHERES
DENSITY
HOT WORKING
PELLETIZING
POWDERS
QUANTITY RATIO
SINTERING
TITANIUM BORIDES
VERY HIGH TEMPERATURE
ZIRCONIUM BORIDES
ATMOSPHERES
BORIDES
BORON COMPOUNDS
ELECTRICAL PROPERTIES
ELEMENTS
FABRICATION
FLUIDS
GASES
MATERIALS WORKING
MOLDING
NITRIDES
NITROGEN COMPOUNDS
NONMETALS
PHYSICAL PROPERTIES
PNICTIDES
RARE GASES
SYNTHESIS
TITANIUM COMPOUNDS
TRANSITION ELEMENT COMPOUNDS
ZIRCONIUM COMPOUNDS
360201* - Ceramics
Cermets
& Refractories- Preparation & Fabrication
360204 - Ceramics
Cermets
& Refractories- Physical Properties