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Beryllium Oxide
BERYLLIA, GLUCINIUM OXIDE
Chemistry
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Hazards
- Beryllium
Miscellaneous
- Family: Flux Source
- Region: None
- Mined At: Unspecified
- Raw Mineral: No
- Generic: No
Notes
Beryllium is a specialty high temperature fluxing oxide available as a pure material in a wide variety of sizes and shapes. It acts as a refractory alone. It can also be used as a modifier and opacifier at lower temperatures. It is manufactured from Beryl (3BeO.Al2O3.6SiO2), an igneous mineral silicate of beryllium and aluminum containing about 12-14% beryllium. Emerald is beryl stained with chromium, aquamarine is blue stained beryl.
It is a very expensive material and thus is only used if another cannot be substituted.
Properties:
Specific Gravity: 3.008
Melting Point: 2650C
Softening Temperature: >2000
Thermal Conductivity (Btu/h/sq. ft/degree F/ft): 150
CTE, 10 -6/degree F, at..
212F: 5.4
932F: 7.4
1832F: 8.9
Tensile Strength, psi (room temperature): 18,000-20,000
(1000C): 5000
Compressive Strength, (room temperature): 200,000
(2000F): 60,000
Transverse Strength, psi: 35,000
Modulus of Elasticity, psi: 40,000-45,000
Beryllia components are formed by hot pressing in graphite molds in induction furnaces, by slip casting, convention drying pressing, and extrusion.
Beryllia main uses are to make microwave tube parts such as cathode supports, envelopes, spacers, helix supports, collector isolators, heat sink and windows, substrates, mounting pads, heat sinks for electronic devices, bores or plasma envelopes for gas lasers. Other uses are electron tube parts, radiation and antenna windows, radar antennae, as crucibles for melting uranium, thorium and beryllium metal. New uses are being developed in chemical and mechanical fields (i.e. aircraft, rockets).
BeO is important in nuclear reactors because of its refractory nature combined with high thermal conductivity and ability to moderate (slow down) fast neutrons. It is used for reflectors, as a matrix material for fuel elements, and uses are being researched for shielding and control rod assembly applications.
As mentioned, Beryllia is valuable for producing ceramics with high thermal conductivity, particularly in the lower temperature ranges. Its thermal conductivity is 400% than of dense alumina at high temperatures and even greater at lower temperatures. Its thermal conductivity is dependent on purity. For example 99.8% purity sees a 10-15% rise in conductivity.
Beryllium has excellent dielectric properties, outstanding resistance to wetting and corrosion by many metals and non-metals. It's mechanical properties are only slightly less than that of 95% alumina ceramics. It has valuable nuclear properties including an exceptionally low thermal neutron absorption cross section. Like alumina, it is readily metallized by thick and thin film techniques.
Data
- Melting Point (MP): 2500C
- Specific Gravity: 3.00
- Specific Gravity: 3.00
- Melting Point (MP): 2500C
Suppliers
- Generic
Authors
- Tony Hansen (Owner)
XML
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