载气对炭/炭复合材料沉积速率、体密度和微观结构的影响

侯振华; 郝名扬; 罗瑞盈; 向巧; 杨威; 商海东; 许怀哲

doi:10.1016/S1872-5805(15)60196-2

载气对炭/炭复合材料沉积速率、体密度和微观结构的影响

doi: 10.1016/S1872-5805(15)60196-2

北京航空航天大学物理科学与核能工程学院, 北京 100191

基金项目: 国家自然科学基金(21071011).

详细信息

作者简介:
侯振华,博士研究生.E-mail:houzhenhualove@126.com

通讯作者:
罗瑞盈,教授.E-mail:ryluo@buaa.edu.cn

中图分类号: TQ342⁺.76
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- 文章访问数: 610
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- PDF下载量: 362
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出版历程
- 收稿日期: 2015-02-25
- 录用日期: 2015-09-07
- 修回日期: 2015-07-20
- 刊出日期: 2015-08-28

Effect of carrier gases on densification rate, bulk density and microstructure of carbon/carbon composites

School of Physics and Nuclear Energy Engineering, Beijing University of Aeronautics and Astronautics, Beijing 100191, China

Funds: National Natural Science Foundation of China (21071011).

摘要

摘要: 分别采用H₂和CO₂作为载气,CH₄为前躯体,通过等温化学气相渗积制备炭/炭复合材料,通过偏光显微镜、拉曼光谱、X射线衍射和透射电镜对材料微观结构表征以及渗积过程密度变化,研究载气对沉积速率、体密度和微观结构的影响规律。结果表明:在渗积前50 h,CH₄-H₂体系的沉积速率明显大于CH₄-CO₂体系,但在其余渗积时间里,CH₄-H₂体系的沉积速率小于CH₄-CO₂体系。当载气从H₂变成CO₂时,复合材料的体密度从1.626 g/cm³增加到1.723 g/cm³,最大径向密度梯度从0.074 g/cm³ 减小到 0.056 g/cm³。同时,基体炭从纯的粗糙体炭转变为杂化粗糙体炭含有过度生长锥,且平均石墨化度从62.7%下降到 50.8%。这些显著的变化是由于CO₂的氧化作用降低了表面沉积速率,却没有降低孔内沉积速率,同时大量的缺陷形成于层状石墨烯结构中导致形成过度生长锥,降低了热解炭织构。
- 炭/炭复合材料 /
- 微观结构 /
- 化学气相渗积 /
- 载气
Abstract: Effect of carrier gases(H₂ and CO₂) on the densification rate, bulk density and microstructure of carbon/carbon composites fabricated by isothermalchemical vapor infiltration from methane (CH₄) was investigated.In the initial 50 h, the densification rate obtained from CH₄-H₂ is obviously higher than that from CH₄-CO₂, while the densification rate from CH₄-H₂ is lower than that from CH₄-CO₂with a further increase of infiltration time. When the carrier gas is switched from H₂ to CO₂, the average bulk density of the compositeincreases from 1.626 to 1.723 g/cm³, the maximum radial density gradient decreases from 0.074 to 0.056 g/cm³, the matrix changes from the pure rough laminar to hybrid rough laminar pyrocarbon with overgrowth cones, and the average degree of graphitization reduces from 62.7% to 50.8%. These significant changes are caused by the fact that CO₂ can effectively reduce the surface deposition rate but does not inhibit the in-pore infiltration, and thatdefects are formed in the deposits by a CO₂ introduction in gas phase and the resulting overgrowth cones deteriorate the texture degree of pyrocarbon.
- Carbon/carbon composites /
- Microstructure /
- Chemical vapor deposition /
- Carrier gas

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参考文献(16)

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载气对炭/炭复合材料沉积速率、体密度和微观结构的影响

doi: 10.1016/S1872-5805(15)60196-2

作者简介:
侯振华,博士研究生.E-mail:houzhenhualove@126.com

通讯作者:
罗瑞盈,教授.E-mail:ryluo@buaa.edu.cn

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Effect of carrier gases on densification rate, bulk density and microstructure of carbon/carbon composites

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留言板

载气对炭/炭复合材料沉积速率、体密度和微观结构的影响

doi: 10.1016/S1872-5805(15)60196-2

作者简介: 侯振华,博士研究生.E-mail:houzhenhualove@126.com

通讯作者: 罗瑞盈,教授.E-mail:ryluo@buaa.edu.cn

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出版历程

Effect of carrier gases on densification rate, bulk density and microstructure of carbon/carbon composites

计量

出版历程

目录

作者简介:
侯振华,博士研究生.E-mail:houzhenhualove@126.com

通讯作者:
罗瑞盈,教授.E-mail:ryluo@buaa.edu.cn