Mechanical and Thermal Behavior of Fibrous Carbon Materials

Abstract

The ability of various commercial fibrous carbon materials to withstand stress and conduct heat has been evaluated through experimental and analytical studies. The combined effects of different micro/macro-structural characteristics were discussed and compared. Large differences in mechanical behavior were observed between the different groups or subgroups of fibrous materials, due to the different types of fibers and the mechanical and/or chemical bonds between them. The application of the Mooney–Rivlin model made it possible to determine the elastic modulus of soft felts, with a few exceptions, which were studied in-depth. The possible use of two different mechanical test methods allowed a comparison of the results in terms of elastic modulus obtained under different deformation regimes. The effective thermal conductivity of the same fibrous materials was also studied and found to be much lower than that of a single carbon fiber due to the high porosity, and varied with the bulk density and the fiber organization involving more or less thermal contact resistances. The thermal conductivity of most materials is highly anisotropic, with higher values in the direction of preferential fiber orientation. Finally, the combination of compression and transient thermal conductivity measurement techniques allowed the heat conduction properties of the commercial fibrous carbons to be investigated experimentally when compressed. It was observed that thermal conductivity is strongly affected under compression, especially perpendicular to the main fiber orientation.

Electrical Resistivity and Microwave Properties of Carbon Fiber Felt Composites

“…The mechanical and thermal properties of these felts have been detailed elsewhere [ 2 ]. Briefly, the elastic moduli of the ex-RC and ex-PAN fiber felts are 0.142 and 0.187 MPa, respectively, with total porosities of 94.6% and 93.8%, respectively.…”

“…In addition, the power of microwave radiation increases with the number of devices operating in the same space and by the rapid advancement of telecommunications, where higher frequencies and thus greater powers are required to transmit a large amount of information. Carbon felts (nonwovens based on carbon fibers) are widely used in various applications due to their unique structural and physical properties, including low electrical resistivity, good mechanical strength, and excellent chemical resistance, as well as commercial availability, lightness, and ease of handling and processing, which allows these structures to be used for various electromagnetic shielding applications [ 2 , 3 , 4 , 5 ].…”

Hybrid Polyethylene Composites with Recycled Carbon Fibres and Hemp Fibres Produced by Rotational Moulding

“…This is because the hybrid composite has more but smaller voids on its surface compared to the hemp-PE composite, as shown in Figure 7a,b. This behaviour is attributed to the high thermal conductivity of the carbon fibre (5 to 15 W•m −1 •K −1 ) [44], which assisted the sintering of the hemp-PE composite pellets during the process. It is known that the amount of formed conductive chains exponentially increases with the content of carbon fibre, thereby increasing the thermal conductivity of a composite [45].…”

“…Porosity (% Area) 50(THU1.5)/50(UCU1.5) 6.8 THU1. 5 7.7 [44], which assisted the sintering of the hemp-PE composite pellets during the process. It is known that the amount of formed conductive chains exponentially increases with the content of carbon fibre, thereby increasing the thermal conductivity of a composite [45].…”

Design and Thermal Conductivity of 3d Artificial Cross-Linked Random Fiber Networks

“…Several researches have been conducted to investigate their mechanical (see Refs. [1][2][3][4][5][6][7][8][9][10][11][12] and references therein), acoustical (see Refs. [13][14][15][16][17] and references therein), and thermal (see Refs.…”