Patent ID: 8703091

Claim:
A manufacturing method of a high modulus graphite fiber having a tensile modulus of 270-650GPa, and comprising a plurality of crystal structures with a thickness (Lc) of 20-70 angstroms, said method comprising the steps of: performing an ultra quick high temperature graphitization process by using a carbon fiber as a raw material and using a microwave focusing method to heat the carbon fiber at a heating speed of 10-100° C. per minute to a temperature equal to a graphitization temperature of 1400-3000° C.; and performing a quick graphitization process for 0.5-10 minutes to form the high modulus graphite fiber, wherein the microwave focusing method provides an elliptical cavity design capable of forming a microwave field concentration area at two focal points of the elliptical cavity separately, and providing an inert gas and a high frequency microwave, so that the electric field of the high frequency microwave and the carbon fiber passing through the microwave field concentration area produce an induced current for heating and produce a high temperature quickly under the protection of an inert gas atmosphere.