Analysis of flaws in high-strength carbon fibres from mesophase pitch

1980 ◽  
Vol 15 (10) ◽  
pp. 2455-2465 ◽  
Author(s):  
Janice Breedon Jones ◽  
John B. Barr ◽  
Robert E. Smith
Keyword(s):  
High Strength ◽  
Mesophase Pitch ◽  
Carbon Fibres

Analysis of flaws in high-strength carbon fibres from mesophase pitch

Composites ◽  
1981 ◽  
Vol 12 (2) ◽  
pp. 146
Keyword(s):  
High Strength ◽  
Mesophase Pitch ◽  
Carbon Fibres

High strength carbon fibres from mesophase pitch

Composites ◽  
1979 ◽  
Vol 10 (4) ◽  
pp. 241
Keyword(s):  
High Strength ◽  
Mesophase Pitch ◽  
Carbon Fibres

New porous silicon carbide composite reinforced by intact high-strength carbon fibres

2006 ◽  
Vol 26 (9) ◽  
pp. 1715-1724 ◽  
Author(s):  
Juliane Mentz ◽  
Marcus Müller ◽  
Meinhard Kuntz ◽  
Georg Grathwohl ◽  
Hans Peter Buchkremer ◽  
...  
Keyword(s):  
Silicon Carbide ◽  
Porous Silicon ◽  
High Strength ◽  
Carbon Fibres ◽  
Porous Silicon Carbide ◽  
Carbide Composite

scholarly journals High strength and low weight hollow carbon fibres

2017 ◽  
Vol 254 ◽  
pp. 042017 ◽  
Author(s):  
T. Köhler ◽  
R. Brüll ◽  
F. Pursche ◽  
J. Langgartner ◽  
G. Seide ◽  
...  
Keyword(s):  
High Strength ◽  
Carbon Fibres ◽  
Low Weight ◽  
Hollow Carbon

Exploring the Thermodynamic Aspects of Structure Formation During Wet-Spinning of Polyacrylonitrile Fibres

2011 ◽  
Vol 1 (2) ◽  
pp. 36-52
Author(s):  
Shahram Arbab ◽  
A. Zeinolebadi ◽  
Parviz Noorpanah
Keyword(s):  
Phase Separation ◽  
High Strength ◽  
Solution Viscosity ◽  
Wet Spinning ◽  
Precipitation Process ◽  
Carbon Fibres ◽  
Electron Scanning Microscopy ◽  
Lower Porosity ◽  
On Line ◽  
Micrometer Size

Wet-spun polyacrylonitrile fibres are the main precursor for high strength carbon fibres. The properties of carbon fibres strongly depend on the structure of the precursor fibre. Polyacrylonitrile fibres were spun from solutions with varying solvent/nonsolvent content and different draw ratios. Wet-spinning is an immersion precipitation process, thus thermodynamic affinity of spinning dope to the coagulation medium was considered as the driving force of phase-separation, while viscosity of the solution accounted for the resistive force against phase separation and growth of the nucleated voids. Thermodynamic affinity was estimated by modifying Ruaan’s theory and viscosity of the solution was assessed on-line by measuring flow rate and back pressure at the spinneret. Hence, the parameter X (thermodynamic affinity/viscosity) was introduced to predict the porous morphology of the fibres. Generally, an increase in X led to fibres with higher porosity. A combination of electron scanning microscopy (SEM), porosimetry and thermoporometry was applied to fully characterize microstructure of fibres. Based on image analysis of SEM micrographs and data obtained from thermoporometry and porosimetry fractions of dense polymer ligament, micrometer size voids (macrovoids) and nanometer size voids (nanovoids) were estimated. Increasing polymer content or nonsolvent content in the spinning dope caused an increase in the solution viscosity and resulted in fibres with lower porosity. Imposing drawing on the as-spun fibres further decreased the porosity. Drawing also shifted the size distribution of nanovoids toward smaller values.

On Optimum Fibre Orientation in an Annulus

1969 ◽  
Vol 73 (703) ◽  
pp. 593-594
Author(s):  
E. H. Mansfield ◽  
Carol Hanson
Keyword(s):  
Fibre Orientation ◽  
High Strength ◽  
Stress Pattern ◽  
Carbon Fibres ◽  
Optimum Arrangement ◽  
Strength And Stiffness ◽  
Applied Stresses

The development of carbon fibres which exhibit high strength and stiffness raises many problems in the design of such fibre reinforced structures. One such problem concerns the optimum arrangement of fibres to support a given load system or load envelope, and this has been treated by Harris for planar load envelopes bounded by given values of applied stresses σX, σY and τXY . Here we consider a problem of optimum fibre arrangement to transfer a torque T across an annulus bounded by inner and outer radii r 0 and kr 0, respectively. This problem is much simpler than Harris', insofar as only one load system is considered, but it differs insofar as the stress pattern is not isotropic.

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