检索结果-南通市图书馆

Effects of dip-coated BN interphase on mechanical properties of sic_f/sic composites prepared by CVI process

Transactions of Nonferrous Metals Society of China 2014年第5期24卷 1400-1406页

作者：周洋周万城罗发朱冬梅西北工业大学凝固技术国家重点实验室西安710072

BN interphase was successfully synthesized on sic fiber fabrics by dip-coating process using boric acid and urea as precursors under N2 atmosphere. The morphology of BN interphase was observed by SEM, and the structure was characterized by XRD and FT-IR spectra. The sicf/sic composites with dip-coated BN interphase were fabricated by chemical vapor infiltration （CVI） process, and the effects ofBN interphase on the mechanical properties of composites were investigated. The results show that the sic fibers are fully covered by BN interphase with smooth surface and turbostratic structure （t-BN）, and the thickness is about 0.4 μm. The flexural strengths of sicf/sic composites with and without BN interphase are about 180 and 95 MPa, respectively. Compared with the as-received sicf/sic composites, the composites with BN interphase exhibit an obvious toughened fracture behavior. From the microstructural analysis, it can be confirmed that the BN interphase plays a key part in protecting the fibers from chemical attack during matrix infiltration and weakening interfacial bonding, which can improve the mechanical properties of sicf/sic composites remarkably.

关键词： sicf/sic composites BN interphase dip-coating CVI mechanical properties

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Effects of thermal oxidation on microwave-absorbing and mechanical properties of sic_f/sic composites with PyC interphase

引用

Transactions of Nonferrous Metals Society of China 2015年第5期25卷 1484-1489页

作者：史毅敏罗发丁冬海穆阳周万城朱冬梅西北工业大学凝固技术国家重点实验室西安710072 西安建筑科技大学材料与矿资学院西安710055

The sicf/sic composites containing PyC interphase were prepared by chemical vapor infiltration process. The influences of thermal oxidation on the complex permittivity and microwave absorption properties of Si Cf/Si C composites were investigated in the frequency range of 8.2-12.4 GHz. Both the real and imaginary parts of the complex permittivity decreased after thermal oxidation. The composites after 100 h thermal oxidation showed that reflection loss exceeded-10 d B in the frequency of 9.7-11.9 GHz and the minimum value was-11.4 d B at 11.0 GHz. The flexural strength of composites decreased but fracture behavior was improved obviously after thermal oxidation. These results indicate that the sicf/sic composites containing PyC interphase after thermal oxidation possess good microwave absorbing property and fracture behavior.

关键词： sicf/sic composites thermal oxidation dielectric properties microwave absorbing mechanical properties

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Oxidation Performance of Ytterbium Disilicate/Silicon Environmental Barrier Coating via Optimized Air Plasma Spraying

Oxidation Performance of Ytterbium Disilicate/Silicon Enviro...

引用

作者： Yingjie Jian Yanfei Wang Rongjun Liu Fan Wan Science and Technology on Advanced Ceramic Fibers and composites Laboratory National University of Defense Technology

Environmental barrier coatings(EBCs) play a critical role in mitigating the degradation of sicf/sic ceramic matrix composites(CMCs) in complex combustion environment, and improve the service life of thermal engine components. In this paper, by adjusting the parameters of atmospheric plasma spraying(APS), the spraying process of ytterbium disilicate(YbSiO)under a lower power has been optimized. A two-layer EBC system consisting of ytterbium disilicate and silicon is prepared on the sicf/sic composite substrate by using optimized technological parameters. The thermal resistance and water oxygen corrosion resistance of such two-layer EBC system are investigated. The results indicate that the current ytterbium disilicate/silicon EBC system exhibits good phase stability, excellent water vapor and oxygen corrosion resistance. However, the exposed silicon bonding layer tends to generate an excessive thermal growth oxide(TGO) layer known as SiO,leading to an early spallation of the coating.

关键词： Environmental Barrier Coating Air Plasma Spraying Ytterbium Disilicate sicf/sic composites

来源： cnki会议评论

在线全文

cnki会议

学校读者我要写书评

暂无评论

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：