Direct electrical cure of carbon fiber composites

This paper presents a study of the cure of carbon fiber composites by the direct application of an electric current. The conductivity of carbon fiber enables the individual fibers to act as heating elements. The result is a large number of heating elements throughout the composite structure. These heating elements locally heat the resin surrounding them, resulting in the resin curing. This study shows that cure of composites is achieved in samples up to 60 X 25 cm. Initially, the required contact arrangement to obtain a uniformly heated panel is assessed and an optimum arrangement achieved. Following this, the change in required energy as the sample thickness and sample length are changed is measured. The degree of cure is compared to conventionally cured composites using differential scanning calorimetry (DSC). Three-point bend testing is used to determine the flexural strength and modulus of the composite samples. The results show that a comparable level of cure can be obtained using direct application of an electrical current as that obtained using autoclave cure and oven cure processes.