Synergistic effect of the glass bead and continuous glass fibers on the low-velocity impact resistance of nylon 6 matrix composites

Glass fiber-reinforced resin matrix composites have good mechanical and impact resistance properties, while with particle co-reinforcement, a synergistic effect can further improve their performance. In this paper, continuous glass fiber-reinforced nylon 6 (GF/PA6) and continuous glass fiber (GF) with glass beads (GBs) co-reinforced nylon 6 (GB-GF/PA6) were prepared to investigate the co-reinforcement mechanism and the synergistic effect of particle and fiber. A quantitative parameter of the residual impact force divided by the critical force Pr/Pcr, as the damage degree of the low-velocity impact, is defined to evaluate the impact resistance of the composite. The results indicate that the damage of GB-GF/PA6 was lower than that of GF/PA6, and the synergistic effect reaches the most obvious at the GB addition of 10 wt%. Scanning electron microscope (SEM) and x-ray computed tomography (XCT) images disclose that GB impedes the type II crack spread in the matrix and fiber/matrix interface. With the type II cracks reducing, the materials' resistance to delamination can be significantly enhanced. For the composite structure, in which 10 wt% GB and 60 wt% GF are introduced, the flexural strength, shear strength, and pendulum impact strength were tested with the maximum values of 379.4 MPa, 53.1 MPa, and 219.0 J/m2, respectively. This composite structure design, presenting a continuous GF and GBs co-reinforce effect, offers a manufacturing process that is easily scalable to achieve excellent characteristics. (A) Crack generation in composite and (B) Crack growth in composite. image