Interfacial carbon fiber–matrix interactions in thermosetting composites volumetrically cured by electromagnetic fields

Abstract

We present a novel out-of-oven method for curing carbon fiber reinforced composites (CFRCs) using radio frequency (RF) fields and assess the effects of fiber heating on the fiber–matrix interfacial properties. In this volumetric heating setup, thermal energy is generated by the carbon fibers interacting with the RF fields (1–200 MHz range) and drives the crosslinking reaction in the epoxy. To study the effect of RF heating and curing on the interfacial properties, we processed composites with carbon fibers embedded in thermosetting resin at varying target curing temperatures and tested these composites using nanoindentation and lap-shear tests that show comparable behavior to conventional oven-cured composites. Experimental characterization is coupled with finite element analysis and reactive molecular dynamics (ReaxFF) simulations to investigate and understand the interfacial properties. This investigation indicates that electromagnetic heating can be used to cure CFRCs rapidly without degrading the fiber–matrix interface.