Effect of carbon fiber surface microstructure on mechanical properties of CCF800

The surface microstructure of 10 samples of CCF800 carbon fibers was quantitatively characterized by the number, width, depth and distribution of grooves. With the help of self-programmed Matlab, the fractured cross-section SEM images were binarization processed and contour extracted, and then the linear equation tangent method was used to identify grooves and to measure width and depth of each groove. Using Weibull distribution equation, shape factor of carbon fiber was calculated by width distribution, as well as roughness by depth distribution. Meanwhile, monofilament tensile strength of each sample was acquired in accordance with ASTM D3379. The comprehensive effect of width, depth, shape factor and roughness on the strength was discussed.