EFFECTS OF CURE CYCLE PRESSURE AND VOIDS ON SOME MECHANICAL-PROPERTIES OF CARBON-EPOXY LAMINATES

The effects of various curing pressures (resulting in different void contents) on some mechanical properties of carbon/epoxy laminates have been examined. Thermogravimetry and mechanical spectrometry were used to determine the initial water content of prepregs and the dependence of viscosity on temperature. The pressure conditions were defined with respect to these preliminary test results. A set of curing pressure routes was then designed to produce unidirectional laminates with void contents between 0.3 and 10 vol%. The mechanical properties of unidirectional laminates depend on the void content and this results in the determination of an optimal curing pressure route which involves minimizing the void content, while the mechanical properties are kept at their maximum level. To allow generalization of the experimental results, this study has been performed on two different composite materials.