Development and implementation of direct electric cure of plain weave CFRP composites for aerospace

Abstract

Curing aerospace composites is time-consuming with high energy requirements, particularly when using methods such as autoclaves, ovens and heated presses. This study investigates direct electric cure (DEC), which uses the Joule effect to directly heat carbon fibre composites to their cure temperature. Its benefits include a significant increase in energy efficiency, control over the cure temperature and low void content compared to oven curing. Samples were manufactured with vacuum-assisted resin transfer moulding (VARTM) and prepreg, as well as curing a two-meter-long leading-edge component, to demonstrate and evaluate the curing method at scale. The average void content for VARTM DEC samples was lower by 0.82 % compared to the oven-cured panel, however, the average degree of cure (DoC) decreased by 6.25 %. Normalised energy consumption for the cure was significantly reduced for all DEC cures, with VARTM cures using 99 % less energy than oven-cured components.