One kind of a large diameter high strength and high modulus PAN-based carbon fiber and its preparation method

The present invention relates to a method for preparing a large-diameter high-strength and high modulus PAN-based carbon fibers. Current-assisted graphitization technology, the use of carbon fibers in a high temperature environment, the conductivity itself, after applying a certain voltage, such that the carbon fibers themselves generate heat, eliminating the conventional graphitization process since the fibers the radial temperature difference due to heat conduction, eliminating fiber graphitization process generated stress the diameter direction of the fiber; while imparting a carbon fiber high modulus, reduce the intensity of graphitization of the carbon fibers is reduced; electron flow through the effect of the fiber axis direction to promote the formation and rearrangement of the graphite crystallite structure of the carbon fibers, thereby obtaining large-diameter high modulus high strength carbon fibers. Diameter can be obtained while having strength of more than 6.0 m 3.5GPa or more, more than 320GPa modulus carbon fibers.