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Three‐dimensional carbon fiber reinforced resin matrix composite can effectively overcome the defects of traditional composite in the interlayer strength and stiffness, and has been widely used. Herein, the threshold infiltration pressure of resin in three‐dimensional carbon fiber preform is respectively calculated as 0.170 and 0.973 MPa from the perspective of statics and dynamics. The static calculation ignores the additional pressure caused by the viscous resistance of the resin during the infiltration process, which deviated greatly from the actual value. Therefore, the dynamics calculation value is used as a reference to extrusion pressure in the experiment. The composites with extrusion pressure of 1, 2, 3, 4, and 5 MPa are prepared by vacuum infiltration hot pressing process. Through the study of the infiltration microstructure and bending fracture morphology of the composite, it is found that when the extrusion pressure is 3 MPa, the preparation effect is the best. At this time, the bending strength of the composite is 540 MPa, which is 92.86% and 71.43% higher than that at 1 and 5 MPa, respectively. It is indicated that the extrusion pressure is a key parameter in the composite preparation process and needs to be selected reasonably. [ABSTRACT FROM AUTHOR]

In order to prepare a carbon-fiber-reinforced polymer composite (CFRP) with ideal microstructure and properties, a new vacuum pressure infiltration CFRP method is proposed based on an analysis of existing CFRP preparation process methods. Research on composite material preparation systems was carried out by using this new method principle. The system mainly includes a fiber pre-forming module, a vacuum heating infiltration module, a hot-press curing molding module, and a data acquisition control module. Under the conditions of natural curing at 0 MPa + 6 h + 25 °C, vacuum heating curing at –0.05 MPa + 30 min + 80 °C, and hot-press curing at 0.7 MPa + 5 min + 50 °C, a two-dimensional (2D) CFRP with excellent microstructure and properties was successfully prepared. Observing the microstructure of the prepared composite material, it can be found that the inside of the composite material was sufficiently and uniformly infiltrated, and common preparation defects such as holes and delamination were effectively controlled. Through the performance test, the bending strength of the material reached 790 MPa. [ABSTRACT FROM AUTHOR]