X-Ray Diffraction Application for the Study of the Fine Structure of Carbon Fibers

The fine structure of carbon fibers, obtained according to specific preparation techniques, has been studied. It has been shown that the fiber material is heterogeneous, its component composition is determined by thermomechanical treatment conditions and addition of boron; also it depends on the angle φ of coherent scattering domain orientation relative to the thread axis. The mean coherent scattering domain sizes increase in transition to the components corresponding to smaller d002 values. Increase in temperature and duration of heat treatment, as well as the presence of a boron-containing additive, ensures formation of the components corresponding to smaller interplanar spacing d002 values in the carbon material. The observed influence of temperature and duration of heat treatment, as well as the angle of coherent scattering domain orientation relative to the thread axis, upon the component composition makes it possible to assume that the process of carbon fiber material transformation into a state of greater stability presumably develops through a number of metastable stages.