Improve the Uniform Distribution of Particles and Reduce Porosity in High-content Spherical Particle Modified Composite: A Vibration-Pressure Hybrid Approach

Abstract CFRP (carbon fiber-reinforced polymer) modified with particles can serve as excellent functional materials. However, high-content doping of particles in the polymer tends to result in particles aggregation and gas entrapment. To address this limitation, a vibration-autoclave hybrid (80-30-10 g + 0.6 MPa) process is developed in this paper. The properties of composites fabricated using this novel method are systematically compared against those from the autoclave high-pressure (0.6 MPa) process and the vibration-vacuum bag (80-30-(5-15 g)) process. The results show that Aluminum (Al) alloy particles under 0.6 MPa process is highly prone to agglomeration in the resin, and 80-30-(5-15 g) process exhibits poor molding performance for the material, which is attributed to the insufficient pressure failing to compact the fiber-resin system. In contrast, 80-30-10 g + 0.6 MPa process effectively overcomes the shortcomings of the two processes. It achieves the highest interlaminar shear strength of 85.43 MPa and the lowest porosity of 0.73%. Besides, image recognition is used to measure the area of Al alloy particles in quantifying the agglomeration degree. It is found that the agglomeration degree in vibration-involved processes decreased by more than 80% compared with the autoclave, which strongly confirms the conclusion that the vibration process promotes the dispersion of Al alloy particles. Finally, scanning electron microscopy (SEM) observations of the particle distribution on the top and side of the composite further verified the superiority of the combined process.