Li Y.,Beihang University |
Zhao Y.,Beihang University |
Liu G.,Aerospace Research Institute of Materials And Processing Technology |
Li S.,Weihai Tuozhan Fiber Co. |
Li L.,Beihang University
Hangkong Xuebao/Acta Aeronautica et Astronautica Sinica | Year: 2014
Surface features of domestic CCF300 carbon fiber, manufacturability, drapability of two types of non-crimp fabrics (NCF, CCF300 45°/-45° and CCF300 0°/90°) and the mechanical properties of NCF reinforced composites are investigated in order to promote the further application of domestic carbon fiber and its NCF in liquid composites molding. The results show that the surface of the domestic CCF300 carbon fiber has high chemical and physical activity. And the NCF of CCF300 0°/90° shows good weaving quality. It is demonstrated that the NCF reinforced composites have the comparativemechanical properties with the unidirectional fabric reinforced composites. Thanks to the combination of good dimensional stability, drapability and formability, NCF has great potential to displace the traditional fabrics.
Bian W.,Harbin Institute of Technology |
Li S.,Harbin Institute of Technology |
Li S.,Weihai Tuozhan Fiber Co. |
Liu Q.,Weihai Tuozhan Fiber Co.
Fuhe Cailiao Xuebao/Acta Materiae Compositae Sinica | Year: 2012
A point of view that the carbon fiber has composite structure is proposed. The relationship between the practical elasticity coefficient of carbon fiber and the crystallinity, micro-fiber orientation and pore conditions was researched based on the micro mechanics theory for mechanical properties of composite materials, the continuous fiber reinforced single plate principle and the properties of microstructure of carbon fiber. The analyzing and calculating methods were obtained, and the main factors which affect the elasticity coefficient were found. A innovative theoretical analysis method and the definite calculation formula were given. The obtained theoretical results are consistent with the experimental results. It is revealed that the pore density, the fiber size and orientation, the crystallinity determine the elasticity coefficient of carbon fiber, which provides theoretical basis to improve the carbon fiber production process.
Wang X.Y.,Harbin Institute of Technology |
Xia L.,Harbin Institute of Technology |
Song L.,Harbin Institute of Technology |
Liu Q.T.,Weihai Tuozhan Fiber CO. |
Wen G.,Harbin Institute of Technology
Applied Mechanics and Materials | Year: 2012
Grain-refined TiB2-TiCTiBx composites were designed and fabricated by reaction hot pressing under 30 MPa at 1800 °C choosing 4.8 Ti-BTiB4C material system with Al, C and SiTiB3Nx as additives. The microstructure of the resultant was homogeneously grain-refined TiB2-TiCx matrix reinforced by AlN-SiC solid solution particles that were embedding tiny TiB2-TiCx crystals. The obtained specimen showed relative high flexural strength of 860±30 MPa and fracture toughness of 13.6±0.3 MPa·m1/2, which can be explained by several toughening mechanisms. © (2012) Trans Tech Publications, Switzerland.
Zhu C.,Shenzhen University |
Zhu C.,CAS Institute of Chemistry |
Yu X.,CAS Institute of Chemistry |
Liu X.,CAS Institute of Chemistry |
And 4 more authors.
Gaofenzi Cailiao Kexue Yu Gongcheng/Polymeric Materials Science and Engineering | Year: 2014
Structural evolution of PAN fibers during pre-oxidation and carbonization was studied with scanning electron microscope, Fourier transform infrared and Raman spectroscopy. The results show that: the characteristic Raman peak appears at 253°C; the content of the carbon ranges from 60% to 70% during the organic-inorganic transition and finally rises up to 95% after the transition; fiber radius decreases gradually below 780°C but rapidly after 780°C as the temperature increases. The results can further deeper the understanding of PAN-based carbon fiber fabrication.
Liu X.,CAS Beijing National Laboratory for Molecular |
Liu X.,University of Chinese Academy of Sciences |
Zhu C.,CAS Beijing National Laboratory for Molecular |
Dong H.,CAS Beijing National Laboratory for Molecular |
And 6 more authors.
Colloid and Polymer Science | Year: 2014
Crosslinked polyacrylonitrile (cPAN) particles with uniform size were synthesized through precipitation polymerization. The as-formed cPAN nanoparticles were dispersed in polyacrylonitrile (PAN) solutions to form microgels with various contents, which were used as model to study the influence of the microgels on the shear and extensional rheology of PAN solutions. Flow curves of steady shear viscosity displayed shear thinning and followed time–temperature superposition principle. The dependency of activation energy on the content of cPAN microgels indicated that introduction of microgels weakened the temperature sensitivity of PAN solutions. For extensional rheology study, we utilized the capillary thinning rheometry to characterize the elongation relaxation time and apparent extensional viscosity. Study of filament thinning dynamics with a series of system strains confirmed that the higher content of cPAN microgels the lower extensional strength and worse spinnability of the PAN solution. © 2014, Springer-Verlag Berlin Heidelberg.