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.

2D-T700/E44 composite materials were prepared by improved compression molding process (ICM) then microstructure and properties of the composites were analyzed and summarized by scanning electron microscope (SEM) and electronic universal testing machine. It is found that defects will occur when the process parameters are not controlled properly and the main defects of composite materials include inadequate resin impregnation, weak interlaminar binding force, fiber displacement warping, hole and brittle fracture. Moreover, there are significant differences in the infiltration microstructure, bending properties, and fracture morphology of the composite materials with different defects. When the defects of weak interlaminar binding force and brittle fracture occur, bending properties of composite materials are relatively low, and they are 220 MPa and 245 MPa, respectively, which reach 34.9% and 38.9% of the bending strength of composite material whose defects are effectively controlled. When the process parameters are reasonable and the defects of the composite materials are effectively eliminated, the bending strength can reach 630 MPa. This will lay a foundation for the preparation of 2D-T700/E44 composite materials with ideal microstructures and properties by ICM.

Graphene is often used to improve interlaminar fracture toughness of carbon fiber/epoxy resin (CF/EP) composites. It is still a challenge to improve the toughness while maintaining the in-layer properties. In this study, 2D graphene oxide carbon fiber reinforced epoxy resin matrix (2D CF-GO/EP) composites were prepared by a vacuum infiltration hot-press forming experimental system (VIHPS), and three-point flexural and end notch flexural (ENF) tests were carried out. With the increase of the fiber mass fraction in the composites, the mode II interlaminar fracture toughness (G_IIC) layers decrease gradually, and the bond property between the fiber and matrix interface layer becomes worse, because the accumulation of dense fiber bundles reduces the matrix penetration ability of cracks. However, the flexural properties increased first and then decreased, and reached the best flexural properties at 64.9%. When the fiber mass fraction is too high, the interlamellar bonding properties will decrease, and the fiber bundles will compress and affect each other. The delamination phenomenon will occur between the layers of the composites, which affects the overall bearing strength and stress limit of the composites. The results of the study show that the composites prepared by VIHPS have excellent mechanical properties, and the content of carbon fiber plays an important role in the influencing factors of the interlaminar and in-layer properties of composites.

The critical infiltration pressures of the matrix in a two-dimensional (2D) carbon fiber preform were calculated theoretically, and the calculated values of the static and dynamic models were 0.115 and 0.478 MPa, respectively. Compared with the dynamic model, there is no viscous resistance or infiltration front gas pressure in the static model, so the static value is obviously lower than the dynamic value. To verify the rationality of theoretical calculation, 2D carbon fiber reinforced plastics (2D-CFRP) with infiltration pressures of 0.5, 0.6, 0.7, 0.8, and 0.9 MPa were prepared by the vacuum infiltration hot pressing molding process. The microstructure of the composite was observed and the bending strength was tested by three-point bending test. The results show that the infiltration pressure has an important influence on the infiltration effect and the bending fracture morphology. When the infiltration pressure is 0.7 MPa, the composite has an excellent infiltration effect. The fibers distribute reasonable in the fracture. Stress can be effectively transferred when the composite material is loaded. And the bending strength of the composite material reaches 627 MPa at this time.

Carbon fiber reinforced shape memory polymer composite (SMPC) is a kind of smart material with shape memory characteristics, which is widely used in aerospace, biomedicine, robotics and other fields. In this paper, SMPC was prepared by heating molding process at five different molding temperatures. The effect of molding temperature on the shape memory performance of SMPC was studied. The results show that the shape memory properties of SMPC are closely related to the infiltration effect during the preparation process. When the molding temperature is 70 degrees C, SMPC has an optimum penetration effect and the preparation defects are effectively controlled. The shape fixing rate is 84.3%, and the shape recovery rate is 94.7%, which lays a foundation for the better application of shape memory composite.