In-situ doping B4C nanoparticles in PAN precursors for preparing high modulus PAN-based carbon fibers with boron catalytic graphitization

2020 ◽  
Vol 200 ◽  
pp. 108455
Author(s):  
Hongji Chen ◽  
Jianxiao Yang ◽  
Qin Shuai ◽  
Jun Li ◽  
Qin Ouyang ◽  
...  
2011 ◽  
Vol 686 ◽  
pp. 778-783 ◽  
Author(s):  
Ya Wen ◽  
Yong Gen Lu ◽  
Xian Ying Qin ◽  
Hao Xiao

Catalytic graphitization of polyacrylonitrile-based carbon fiber by doping boric acid was reported in this paper. The microstructure and mechanical properties of polyacrylonitrile-based carbon fibers with and without doping boric acid after heat treatment of 1300°C,1500°C,1800°C, 2100°C,2300°C,2400°Cand 2500°Cwas investigated by X-ray diffraction (XRD) and mechanical testing. The results showed that the tensile modulus of the carbon fibers either boron modified or not, increased obviously with increasing temperatures, and that of the modified carbon fibers was much higher than the unmodified fibers at all temperatures, reaching 404Gpa when the fiber was graphitized at 2500°C. The tensile strength of the modified carbon fibers was lower than the unmodified ones after being graphitized at temperatures below 2300°C, but increased to 2.69 GPa and 2.46 GPa respectively after the fibers were treated at 2300°C and 2500°C, which were higher than that of unmodified fibers treated under the same conditions, indicatinging that the mechanism of boron catalytic graphitization changed at the temperatures higher than 2300°C. It also showed that the interlayer spacing (d002) decreased, while the crystallite size (Lc) and the orientation increased with increasing temperatures.


Author(s):  
V. Serin ◽  
K. Hssein ◽  
G. Zanchi ◽  
J. Sévely

The present developments of electron energy analysis in the microscopes by E.E.L.S. allow an accurate recording of the spectra and of their different complex structures associated with the inner shell electron excitation by the incident electrons (1). Among these structures, the Extended Energy Loss Fine Structures (EXELFS) are of particular interest. They are equivalent to the well known EXAFS oscillations in X-ray absorption spectroscopy. Due to the EELS characteristic, the Fourier analysis of EXELFS oscillations appears as a promising technique for the characterization of composite materials, the major constituents of which are low Z elements. Using EXELFS, we have developed a microstructural study of carbon fibers. This analysis concerns the carbon K edge, which appears in the spectra at 285 eV. The purpose of the paper is to compare the local short range order, determined by this way in the case of Courtauld HTS and P100 ex-polyacrylonitrile carbon fibers, which are high tensile strength (HTS) and high modulus (HM) fibers respectively.


Author(s):  
G. F. Zhelezina ◽  
V. G. Bova ◽  
S. I. Voinov ◽  
A. Ch. Kan

The paper considers possibilities of using a hybrid fabric made of high-modulus carbon yarn brand ZhGV and high-strength aramid yarns brand Rusar-NT for polymer composites reinforcement. The results of studies of the physical and mechanical characteristics of hybrid composite material and values of the implementation of the strength and elasticity carbon fibers and aramid module for composite material are presented. 


2021 ◽  
Vol 199 ◽  
pp. 113820
Author(s):  
Thomas J. Cochell ◽  
Raymond R. Unocic ◽  
José Graña-Otero ◽  
Alexandre Martin

2021 ◽  
pp. 161638
Author(s):  
Ruoyu Chen ◽  
Xinxin Jin ◽  
Daqian Hei ◽  
Peng Lin ◽  
Feng Liu ◽  
...  

1977 ◽  
Vol 99 (4) ◽  
pp. 401-407 ◽  
Author(s):  
T. Tsukizoe ◽  
N. Ohmae

Wear between unidirectionally oriented fiber-reinforced-plastics and mild steel has been investigated. The wear behavior was found to be greatly influenced by the sliding direction, the mechanical properties of fiber-reinforced-plastics and by the tribological properties of fiber-reinforcements or matrices. A summarization of wear-resistance of seven different kinds of fiber-reinforced-plastics signified that the epoxy resin reinforced with high-modulus carbon fibers was the best wear-resistant fiber-reinforced-plastics.


1972 ◽  
Vol 45 (12) ◽  
pp. 3710-3714 ◽  
Author(s):  
Sugio Otani ◽  
Shoji Watanabe ◽  
Hosaku Ogino ◽  
Kazuo Iijima ◽  
Teruyo Koitabashi
Keyword(s):  

2021 ◽  
Vol 21 (10) ◽  
pp. 5235-5240
Author(s):  
Hua-Hui Chen ◽  
Jing-Jing Cao ◽  
Hai-Ping Hong ◽  
Nan Zheng ◽  
Jie Ren ◽  
...  

In Situ transformed carbon fibers/Al2O3 ceramic matrix nanocomposites with Cao–MgO–SiO2 sintering agent were prepared by hot-pressed sintering technology in vacuum. In the sintering process, pre-oxidized polyacrylonitrile fibers (below named as pre-oxidized PAN fibers) were used as the precursors of In Situ transformed carbon fibers. The micro/nanostructure of composites and interface between In Situ transformed carbon fibers and matrix were investigated, as well as the properties of composites. The results showed that the composites could be sintered well at a relatively low temperature of 1650 °C. During the sintering, the precursors, pre-oxidized PAN fibers, were In Situ transformed into carbon fibers, and the In Situ transformed carbon fibers had the graphitelike structure along the fiber axial direction. The carbon atoms arrangement in the surface layer of the fiber was more orderly than the core. A typical diffraction peak of carbon fiber at 26°, which corresponded to the (002) crystal plane, was observed, and the inter-planar spacing was approximately 0.34 nm. The CaO–MgO–SiO2 sintering agent formed MgAl2O4 and CaAl2Si2O8 phases in the interface between In Situ transformed carbon fibers and matrix, therefore improving the interface bonding, and thereby modifying the mechanical properties of the composites.


Author(s):  
V. V. Kulakov ◽  
M. I. Pankov ◽  
V. A. Sivurova ◽  
M. S. Luchkin ◽  
A. K. Golubkov ◽  
...  

The efficiency of the pyrolytic carbon compaction process by decomposing methane in samples of a carbon-carbon composite randomly reinforced with discrete high-modulus (graphitized) carbon fibers with different densities is investigated. The analysis of the test results of samples for determining the compressive strength, determining the densities of samples after compaction with pyrocarbon and after compaction by impregnation and carbonization under pressure is carried out. Scanning electron microscopy (SEM) was used to study the structure of material samples with different initial density values.


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