Metallization of Carbon Fiber Reinforced Polymers By Cold Spray for Lightning Strike Protection

Carbon fiber reinforced polymers (CFRP) have taken over from aluminum for aircraft structures for lightweight purpose, but this leaves vulnerability for lightning strike. To make polymers lightning strike proof, a conductive media must be either embedded in or coated on the polymers. Cold spray is one approach to achieve this. The aim of this work is to cold spray a metal coating with sound mechanical properties and good electrical and thermal conductivity on CFRPs used in aircraft for lightning strike protection. Copper, aluminum and tin were used as the coating materials, and different gas pressure and preheating temperature combinations were used for the cold spray process. Erosion was found to be the key obstacle to develop continuous coatings on the CFRP substrates, although particle embedment could be found in the residual epoxy.