Dependence of the mechanical properties, morphology, and structural characteristics of different types of carbon fibers on treatment temperature

A comparative study was made of three types of carbon fibers subjected to high-temperature treatment at 2000, 2400, and 2800°C in the static regime. The mechanical properties of the initial and heat-treated fibers were studied by scanning electron microscopy, x-ray diffraction, and laser mass spectrometry. Analysis of the surface morphology and structural characteristics of the fibers showed that the two types of fibers obtained with the use of an organic solvent as the precursor have similar structural and mechanical characteristics. Their treatment at 2400°C was accompanied by a slight decrease in strength characteristics and a change in the morphology of the surface. At the same time, the carbon fibers that were made based on a precursor obtained with the use of sodium rhodanide had a more distinct morphology and underwent a marked reduction in strength at temperatures >2000°C. This result might be related to the differences in the conditions under which these fibers were formed, the type of solvent used, and the fibers’ chemical composition.