Hejun Li Haibo Ouyang Lehua Qi Yulei Zhang Zhengjia Li Jianfeng Wei
材料科学技术（英文）
The influence of reaction temperature on the preparation of SiC coating on carbon fibers by the reaction of silicon monoxide with the deposited pyrolytic carbon (PyC) layer has been discussed. With rising reaction temperature, the thickness of SiC layer increases and the SiC grain is coarsening. The apparent activation energy for the synthesis of SiC layer is about 103.3 kJ/mol. The oxidation resistance of carbon fiber can be improved by the SiC/PyC layers significantly. The initial oxidation temperature of the SiC/PyC coated carbon fiber is about 300°C higher than that of the uncoated carbon fiber. The oxidation of the SiC/PyC coated carbon fiber is owing to the diffusion of oxygen through the cracks generated by the mismatch of thermal expansion.
关键词:
Carbon fiber
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null
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null
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null
Wu YAO
材料科学技术（英文）
By heating up the embedded carbon fiber reinforced cement based material (CFRC), the carrying capacity and deformation of concrete member could be adjusted. The relationship between temperature difference and expansion strain of CFRC was demonstrated, and the temperature-deformation-load effect of concrete embedded with CFRC was studied. Heating the CFRC up to different temperatures resulted in different degree of inner pre-stress in concrete. Thus, the load capacity of concrete could be regulated owing to counteracting the pre-stress.
关键词:
Carbon fiber
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null
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null
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null
Yunxia GUO
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Jie LIU
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Jieying LIANG
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null
材料科学技术（英文）
Surface of polyacrylonitrile (PAN)-based carbon fibers was modified by electrochemical oxidation. The modification effect on carbon fibers surface was explored using atomic force microscopy (AFM), X-ray photoelectron spectroscopy (XPS) and X-ray diffraction (XRD). Results showed that on the modified surface of carbon fibers, the carbon contents decreased by 9.7% and the oxygen and nitrogen contents increased by 53.8% and 7.5 times, respectively. The surface roughness and the hydroxyl and carbonyl contents also increased. The surface orientation index was reduced by 1.5% which decreased tensile strength of carbon fibers by 8.1%, and the microcrystalline dimension also decreased which increased the active sites of carbon fiber surface by 78%. The physical and chemical properties of carbon fibers surface were modified through the electrochemical oxidative method, which improved the cohesiveness between the fibers and resin matrix and increased the interlaminar shear strength (ILSS) of carbon fibers reinforced epoxy composite (CFRP) over 20%.
关键词:
Polyacrylonitrile (PAN)
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null
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null
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null
Zuquan TANG
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Zhuoqiu LI
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Jueshi QIAN
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Kejin WANG
材料科学技术（英文）
Carbon fiber reinforced concrete (CFRC) is a kind of good electrothermal material. When connected to an external power supply, stable and uniform heat suitable for deicing application is generated in the CFRC slab. Electric heating and deicing experiments of carbon fiber reinforced concrete slab were carried out in laboratory, and the effect of the temperature and thickness of ice, the thermal conductivity of CFRC, and power output on deicing performance and energy consumption were investigated. The experimental results indicate that it is an effective method to utilize the thermal energy produced by CFRC slab to deice. The time to melt the ice completely decreases with increasing power output and ice temperature, and increases with increasing thickness of the ice. The energy consumption to melt 2 mm thickness of ice varies approximately linearly from 0.556 to 0.846 kW•h/m2 as the initial temperature ranges from -3℃ to -18℃. CFRC with good thermal conduction can reduce temperature difference in CFRC slab effectively.
关键词:
Electrically conductive concrete
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null
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null
Jun QIU
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Xiaoming CAO
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Chong TIAN
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Jinsong ZHANG
材料科学技术（英文）
A novel super-hybrid composite (NSHC) is prepared with three-dimension reticulated SiC ceramic (3DRC), high performance carbon fibers and modified phenolic resin (BPR) in this paper. Ablation performance of super-hybrid composite is studied. The results show that the NSHC has less linear ablation rate compared with pure BPR and CF/BPR composite, for example, its linear ablation rate is 50% of CF/BPR at the same fiber content. Mass ablation rate of the NSHC is slightly lower than that of pure BPR and CF/BPR composite because of their difference in the density. Scanning electron microscopic analysis indicates that 3DRC can increase anti-erosion capacity of materials because its special reticulated structure can control the deformation of materials and strengthen the stability of integral structure.
关键词:
Ablation performance
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null
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null
Dongxin HE
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Chengguo WANG
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Yujun BAI
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Bo ZHU
材料科学技术（英文）
To find out the high-quality polyacrylonitrile (PAN) fibers, some differences are sought by comparing domestic PAN fibers with the foreign ones. X-ray diffractometer (XRD), transmission electron microscope (TEM), Fourier transform infrared (FT-IR) spectrometer, elemental analyzer, tensile-testing machine and high-temperature differential scanning calorimeter (DSC) are used to characterize the individual microstructure, chemical structure, elemental content, mechanical properties and thermal properties. It is found that high-quality PAN fibers have high density, lower titre, higher or adequate tensile strength, and they also have better conglomeration structure, smaller crystal dimension with dispersive distribution, less microvoids and flaws.
关键词:
Polyacrylonitrile (PAN) fiber
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聚丙烯腈纤维
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碳纤维
颜鸿斌
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安明康
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王健
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季雪松
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刘胜利
宇航材料工艺
doi:10.3969/j.issn.1007-2330.2014.04.014
织物用国产碳纤维的性能评价及改进、碳纤维缝编工艺技术的研究等均需要一些必要的分析评估手段.上机织造比较分析表明,碳纤维本身的特性、导纱机件材料与结构形式、送纱方式等工艺设备和技术路线对碳纤维缝编工艺性能影响较大,国产HF10-12K碳纤维的缝编工艺效率和质量明显低于T700-12K碳纤维的;采用旋转轮导纱结构和主动送纱方式等,可有效提高国产碳纤维在碳纤维缝编织物制备工艺质量和工艺效率.结果表明,碳纤维毛羽是影响碳纤维缝编织造工艺质量和效率的关键因素,参数“纱线毛羽指数”、“织物拉伸强力/原纱强度(比值)”和“织物增强树脂基复合材料拉伸强度/原纱强度(比值)”可用来定量比较分析和评估各碳纤维纱线的缝编织造工艺差异性.
关键词:
碳纤维
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缝编
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工艺
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评估
郑斌
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黄娜
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陈聪慧
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胡胜泊
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冯志海
宇航材料工艺
doi:10.3969/j.issn.1007-2330.2010.02.028
利用Image Pro Plus和Photoshop等图像处理软件对三种典型碳纤维样品断面的扫描电镜照片进行了图像分析及处理,使用Matlab对图像进行了数字化处理,计算得到国产1~#及2~#碳纤维样品的圆度分别是0.980和0.809,与,T300碳纤维的圆度0.846有一定差异.通过该方法可以定量化地表征碳纤维表面的物理特征.
关键词:
碳纤维
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扫描电镜
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图像处理
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圆度
