Fiber Orientation Control of Short Fiber Composites: Experiment

Orientation control of short fibers in a liquid matrix has been carried out by loading a magnetic field. Nickel coated graphite short fiber was used as a magnetic inductive fiber. From a practical point of view, main attention was placed upon the determination of the critical volume fraction of the fibers V fc , which was the maximum value at which the ori entation control was possible. V fc was experimentally shown to increase rapidly with decrease of aspect ratio of the fibers. Then, in order to force the increase of V fc , ultrasonic vibration combined with the magnetic moment was loaded to loosen tangled fibers. The loading of the ultrasonic vibration had a remarkable effect in raising the V fc .