材料期刊网

The Infiltration Process and Texture Transition of 2D C/C Composites

Hejun Li

材料科学技术（英文）

2D needle-punched fiber felt was infiltrated by a kind of rapid isothermal chemical vapor infiltration technique. The infiltration process and texture transition of the infiltrated C/C composites were investigated. The porosity and the variations of the cumulative pore volume were determined by mercury porosimetry. The texture of matrix carbon was studied under a polarized light microscope. The results show that the relative mass gain of the sample increases directly as the infiltration time at the initial stage until 20 h, and subsequently the increasing rate of the relative mass gain decreases gradually with the prolonging of infiltration time. Three layers of pyrocarbon were formed around fibers. Low-textured pyrocarbon was obtained at the initial stage. With the densification going on, high-textured pyrocarbon was formed on the surface of low-textured pyrocarbon. Then, low-textured pyrocarbon was produced again during the final stage of densification. The texture transition is ascribed to the variation of the ratio of cumulative inner surface area to volume of pores and the gas partial pressure in pores.

关键词: C/C composites , Isothermal chemical vapor infiltration (ICVI) , Pyrocarbon , Mercury porosimetry , Polarized light microscope

A Multi-interlayer LMAS Joint of C/C-SiC Composites and LAS Glass Ceramics

Qiangang Fu , Fengling Zhao , Hejun Li , Han Peng , Xiaoying Nan

材料科学技术（英文）

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SiC Nanowires Toughed HfC Ablative Coating for C/C Composites

Hejun Li , Yongjie Wang , Qiangang Fu , Yanhui Chu

材料科学技术（英文）

关键词:

Ablative Property of C/C-SiC-HfC Composites Prepared via Precursor Infiltration and Pyrolysis under 3,000℃ Oxyacetylene Torch

Min Yan , Hejun Li , Qiangang Fu , Jing Xie , Lei Liu , Bo Feng

金属学报(英文版) doi:10.1007/s40195-014-0110-y

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Effect of SiC Location on the Ablation of C/C-SiC Composites in Two Heat Fluxes

Lei Liu , Hejun Li , Kui Hao , Xiaohong Shi , Kezhi Li , Chang Ni

材料科学技术（英文）

关键词:

Ablative and Mechanical Properties of C/C-ZrC Composites Prepared by Precursor Infiltration and Pyrolysis Process

Kezhi Li , Jing Xie , Hejun Li , Qiangang Fu

材料科学技术（英文）

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Effect of Bonding Temperature on the Microstructures and Strengths of C/C Composite/GH3044 Alloy Joints by Partial Transient Liquid-Phase (PTLP) Bonding with Multiple Interlayers

Xin Zhang , Xiaohong Shi , Jie Wang , Hejun Li , Kezhi Li , Yancai Ren

金属学报(英文版) doi:10.1007/s40195-014-0090-y

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ON SPINODAL BOUNDARIES OF Al-Li ALLOYS

WEI Yinghui , WANG Xiaotian (School of Materials Scince and Engineering , Xi'an Jiaotong University , Xi'an 710049 , China Manuscript received 10 Mareh , 1994)

金属学报(英文版)

The spinodal decomposition can occur in Al-Li alloys containing 5.8-14.2 at.% Li at room temperature. The modutated structure wavelength is approximately 3.1 nm for com mercial Al-LI alloys. The limit composition of the miscibility gap is 3.66 -16.06 at.%Li at 298 K. The highest temperature of the miscibility gap is 377 K.

关键词: : Al-Li alloy , null , null

大爆炸核合成相关的8Li(d, p)9Li反应截面测量

李志宏 , 柳卫平 , 白希祥 , 郭冰 , 连钢 , 颜胜权 , 王宝祥 , 陆昀 , 曾晟 , 苏俊

原子核物理评论 doi:10.3969/j.issn.1007-4627.2005.01.006

利用8Li次级束测量了质心系能量7.8 MeV 2H(8Li, 9Li)1H反应的角分布, 导出了8Li(d, p)9Li反应的天体物理S因子及9Li→8Li+n虚衰变的渐近归一化系数.

关键词: 8Li(d,p)9Li反应 , 角分布 , 天体物理S因子 , 渐近归一化系数

CRYSTAL STRUCTURE OF γ-Li_xFe_2O_3 WITH ELECTROCHEMICAL INSERTION OF Li

HUANG Jianshun CHEN Junming Shanghai Institute of Metallurgy , Academia Sinica , Shanghai , China Research Associate , Shanghai Institute of Metallurgy , Academia Sinica , Shanghai 200050 , China

金属学报(英文版)

Crystal structure of γ-Li_xFe_2O_3,inserted Li electrochemically,was studied by Moss- bauer spectroscopy together with X-ray diffraction,XPS and electrochemical method,On the insertion of Li at low current density,the crystal structure is keeping original spinel; while at higher current density or by thermal activation,owing to violent movement of Li~+ ions,part of crystal structure transforms into rock type similar to face-centered cubic structure of ferrous oxide.The transition channels during insertion of Li~+ ions and limitation of Li~+ ions inserted were discussed.

关键词: null , null , null