| 查看: 209 | 回复: 3 | ||
| 当前主题已经存档。 | ||
| 【悬赏金币】回答本帖问题，作者lwglwg将赠送您 10 个金币 | ||
| 当前只显示满足指定条件的回帖，点击这里查看本话题的所有回帖 | ||
lwglwg木虫 (职业作家)
|
[求助]
求助:HfB2的熔化热是多少?
|
|
| 求助:HfB2的熔化热是多少?请给出出处哈,急需,感谢! |
回复此楼» 猜你喜欢
一志愿北京化工大学 070300 学硕 336分 求调剂
已经有4人回复
-
352求调剂
已经有3人回复
-
一志愿东华大学化学070300，求调剂
已经有8人回复
-
277材料科学与工程080500求调剂
已经有7人回复
-
317求调剂
已经有18人回复
-
293求调剂
已经有5人回复
-
280分求调剂 一志愿085802
已经有7人回复
-
0854电子信息求调剂
已经有3人回复
-
263求调剂
已经有4人回复
-
石河子大学（211、双一流）硕博研究生长期招生公告
已经有3人回复
lwglwg
木虫 (职业作家)
- 应助: 1 (幼儿园)
- 金币: 8885.2
- 散金: 1430
- 沙发: 1
- 帖子: 4705
- 在线: 561.2小时
- 虫号: 443239
- 注册: 2007-10-27
- 性别: GG
- 专业: 固体力学
3楼2007-12-08 10:41:38
|
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
lwglwg
木虫 (职业作家)
- 应助: 1 (幼儿园)
- 金币: 8885.2
- 散金: 1430
- 沙发: 1
- 帖子: 4705
- 在线: 561.2小时
- 虫号: 443239
- 注册: 2007-10-27
- 性别: GG
- 专业: 固体力学
4楼2007-12-10 15:52:08
