▎ 摘　　要

NOVELTY - The gas pressure forming process involves preparing mixed powder, preparing molds, and carrying out mold filling, air pressure forming, carbonization, surface processing and high temperature ceramicization. The pressurization conditions in the air pressure forming process includes the pressurization at a constant speed at room temperature, the pressure at a constant speed is 5-20 MPa, the pressurization time is 20-50 minutes, and the pressure holding time is 10-40 minutes. The mixed powder contains 15-40 %mass, preferably 20-30 %mass chopped carbon fiber, 30-50 %mass, preferably 40-50 %mass phenolic resin powder, 5-20 %mass, preferably 10-20 %mass silicon powder, and 10-25 %mass, preferably 10-20 %mass graphite powder. The 5-hydantoin acetic acid in the mixed powder is used to modify the oxidized graphite powder to obtain modified graphite powder. USE - Gas pressure forming process for carbon fiber composite materials such as carbon/carbon or carbon/carbon-silicon carbide double-matrix composite materials used in lithium-ion batteries of new energy vehicles. ADVANTAGE - The preparation method of modified graphite powder has higher mechanical properties. The silicon carbide anti-oxidation components are generated in the matrix structure, to improve the anti-oxidation performance of the material. The preparation method has more excellent anti-oxidation protection performance to improve the mechanical properties of the carbon fiber composite material. The uniformity of the mixed powder is increased, and the carbonization under high temperature conditions enables the mixed powder to better complete the reaction of silicon and carbon. A carbon fiber composite material with excellent mechanical properties is not prone to cracking, and has excellent oxidation resistance. The carbon fiber composite material can further increase the product density by chemical vapor phase densification (CVD) or resin impregnation-carbonization of the sagger product after ceramic treatment. DESCRIPTION OF DRAWING(S) - The drawing shows an infrared spectrogram of graphite, graphene oxide and modified graphite powder. (Drawing includes non-English language text)