Composite laminates reinforced by vertically aligned carbon nanotubes: Detailed manufacturing process, from nanotubes transfer to composite consolidation

Nano-constituent incorporation into composites has been extensively studied in the literature due to its improvement in static and dynamic mechanical properties, as well as its prevention from interlaminar crack initiation and propagation. This work introduces a detailed manufacturing process of nano-engineered composite laminates, from impregnation to consolidation, without damaging the initial morphology of carbon nanotubes transferred on prepreg interfaces. Based on prepreg and vertically aligned carbon nanotubes (VACNTs) synthesized on an aluminium alloy (Al) substrate, the impregnation step allows for the transfer of VACNTs onto the prepreg surface through partial resin-rising capillarity. The Al alloy substrate is then removed from the VACNTs through a separation step, ensuring highly effective and repeatable transfer with more than 80% VACNTs transferred onto the prepreg surface. This paper provides insight into the impregnation and transfer processes and guides the choice of process parameters to ensure minimal VACNTs buckling during the consolidation of the hybrid composites at high pressure in an autoclave.