Effect of Surface Modification of Carbon Fiber Based on Magnetron Sputtering Technology on Tensile Properties

In this study, carbon films were constructed on the surface of carbon fibers using magnetron sputtering to improve the surface defects and mechanical properties of carbon fibers. The tensile properties of the single carbon fiber and multifilament carbon fiber before and after modification were tested, and the influence of the modification method on the tensile properties of the carbon fiber was analyzed. Moreover, the effect of the modification process on the dispersion of the tensile breaking strength of the carbon fiber was analyzed using the Weibull distribution. The magnetron sputtering process based on a carbon target successfully repaired the surface and improved the dispersion of the tensile breaking strength of the carbon fiber. After surface modification, the CV value of the breaking strength of the single carbon fiber and multifilament carbon fiber decreased by up to 57.5% and 31%, respectively. The Weibull modulus m of the modified single carbon fiber increased. Furthermore, the surface modification of the carbon fibers by magnetron sputtering was conducive to improving the tensile properties of the carbon fibers. The tensile breaking strength of the modified single carbon fiber and multifilament carbon fiber slightly increased. As the magnetron sputtering time was increased, the tensile breaking strength of the carbon fiber further increased. The influence of the carbon film on the surface of the carbon fiber greatly enhanced the tensile fracture toughness using the crack effect mechanism.