Carbon nanofiber paper for lightning strike protection of composite materials

Carbon fiber reinforced polymer matrix composites have been increasingly used for aircraft structures. Such relatively low-conductivity composite materials need to be engineered with lightning strike protection to achieve lightning tolerance comparable to metallic components. This study developed a specialty paper made of carbon nanofibers and nickel nanostrands as a surface layer on the composite panels and explored potential replacement for existing lightning strike protection materials. The porous, flexible, non-woven papers of nanofibers and nanostrands were first prepared by the papermaking process. They were then incorporated onto the surface of carbon fiber reinforced polymer composites through resin transfer molding process. A method of applying a temporary surface barrier on the paper was developed to prevent the infused resin from breaching the paper’s surface. This minimized the resin on the composite panel’s surface and allowed its surface conductivity to remain high. The lightning strike tests conducted on these composite panels showed that lightning strike tolerance correlated to the surface conductivities of composite panels.