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lwglwg

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h1u2a3n4g

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Subcategory: Boride

Key Words: HfB2, Boron

Material Notes: Gray hexagonal crystals

Physical Properties        Metric                English              Comments

Density                     10.5 g/cc             0.379 lb/in2

Molecular Weight       200.11 g/mol        200.11 g/mol

Thermal Properties

Melting Point            3100 0C                5610 ?F

Descriptive Properties

CAS Number                          12007-23-7

Color                                     Gray

Crystal Structure                    Hexagonal


Heat capacities of HfB2.035 and HfC0.968 from 5 to 350 K



hafnium diboride

Hafnium diboride is an ultra-high temperature ceramic. It has a melting temperature of about 3250 degrees Celsius. It is an unusual ceramic, having relatively high thermal and electrical conductivities. It is a grey, metallic looking material. Hafnium diboride has a hexagonal crystal structure, a molar mass of 200.11 grams per mole, and a density of 10.5 grams per cubic centimeter.

Hafnium diboride is often combined with carbon, boron, silicon, silicon carbide, and/or nickel to improve the consolidation of the hafnium diboride powder (sintering). It is commonly formed into a solid by a process called hot pressing, where the powders are pressed together using both heat and pressure.

The material has potential for use in hypervelocity reentry vehicles such as ICBM heat shields or aerodynamic leading-edges, due to its strength and thermal properties. Unlike polymer and composite material, HfB2 can be formed into aerodynamic shapes that will not ablate during reentry. This inorganic compound-related article is a stub. You can help Wikipedia by expanding it.

This entry is from Wikipedia, the leading user-contributed encyclopedia. It may not have been reviewed by professional editors (see full disclaimer)
2楼2007-12-08 10:12:13
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lwglwg

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h1u2a3n4g

你好!首先感谢你提供的资料,但你并没有提供HFB2的熔化热呀?能给出熔化热的数据吗?急需非常感谢!
作为感谢对你上面提供的东西我愿意给您2个金币作为感谢,怎么转给您由于我是新手不知道怎么转,麻烦版主帮助吧!感谢!

[ Last edited by lwglwg on 2007-12-8 at 10:43 ]
3楼2007-12-08 10:41:38
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lwglwg

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求助:HfB2的熔化热是多少?

求助:HfB2的熔化热是多少?  急需,哪位大虾可以提供帮助,感谢!
4楼2007-12-10 15:52:08
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