Fiber orientation and flexural properties of short carbon fiber/epoxy composites

抄録

In this paper, we investigated fiber orientations and flexural properties of composites, which were prepared from epoxy resin, curing agent and short carbon fiber (CF) below critical fiber length. The prepreg with CF, curing agent and epoxy resin was prepared by an extrusion method. We found that the fiber orientation was caused when the CF/epoxy composite exhibited a plastic behavior. The ratio of this fiber orientation was 0.71 within the angle from 0 to 10°. The flexural modulus and the flexural strength of this composite, which was prepared from fiber orientation prepreg, was 16 GPa and 211 MPa, respectively. The flexural properties were ca. twice large as compared to a composite with random direction of fibers, indicating that the flexural properties were significantly affected by the orientation of fibers even if the fiber was below critical length. Moreover, it was discussed that the effective coefficient of the short fiber orientation distribution was one of important factors to predict the flexural modulus of a composite.