Abstract
Cold spray metallization of carbon fiber-reinforced polymers (CFRP) has attracted increasing interest for potential applications in providing lightning strike protection (LSP) to aircraft. This study aims to assess the LSP performance of cold-sprayed copper and aluminum coatings on a Polyaryletherketone (PAEK)-based carbon fiber-reinforced thermoplastic polymer (CFRTP). Lightning strike tests with a peak current of 70 kA were performed on full-surface copper and aluminum coatings, and grid-patterned aluminum coatings. The lightning strike process was captured by a high-speed camera to investigate the fracture behavior of the cold-sprayed CFRTP specimens. Results revealed that the full-surface copper coating, which had higher electrical resistivity and was thinner than the aluminum coating, experienced explosive coating fractures. Conversely, the aluminum coating incurred less damage, effectively protecting the underlying CFRTP from lightning current without visible ply lift or carbon fiber fracture. Furthermore, grid-patterned aluminum coatings also exhibited LSP capabilities, with their denser mesh reducing both the area of coating fractures and the thermal damage to the CFRTP surface.
