Relaxation of temperature deformations in carbon fibers

Electrical Resistivity and Microwave Properties of Carbon Fiber Felt Composites

“…We suppose that the reason for this instability is the reduction in the linear dimension of the carbon fibers in the direction of the composite reinforcement (when the matrix expands), which leads to the increase in resistivity. The carbon fibers lose their ability to shrink after a few repeated temperature cycles [ 11 ]. The intensity of this effect depends on the nature of the fiber material or its diameter; it is larger for composites with polyacrylonitrile-based carbon fibers that are almost twice as thick as those derived from regenerated cellulose, and weakly depends on the direction of current flow.…”

“…Composites with epoxy resin as the polymer matrix and carbon particles as the filler are used in a variety of modern technologies, such as functional layers in electronic devices; as strong electrostatic protective and charge-elimination materials in the aerospace industry, robotic structures and automotive components; and in the rapidly expanding lithium-ion battery industry [ 6 , 7 , 8 , 9 , 10 , 11 ]. Such materials indeed have special properties of resistance to mechanical stress, humidity and aggressive environments, radiation, high temperature, and thermal cycling [ 12 , 13 , 14 ].…”

“…Carbon fiber-reinforced polymer composites have very high specific strength and modulus of elasticity but are subject to mechanical damage due to heat; the materials undergo mechanical stress as the temperature increases, resulting in delamination between the layers [ 13 ]. This leads to shrinkage of the carbon fibers, so that the linear dimensions in the direction of reinforcement decrease [ 11 ]. Commercial applications of new materials require stability of their characteristics and a complete understanding of the physical phenomena that take place under varying environmental and operating conditions.…”