Response of electroless copper coated CFRP laminates to emulated lightning strikes

[Display omitted] •Copper electroless as a sacrificial protection in lightning strike of composites.•Chemical deposition is cheaper than metallic meshes and allow protection tuning.•Charge transfer is related with the damages in lightning emulation of composites.•Defects in protection cause leakages of current to conductive carbon fibers.•Currents reaching the substrate responsible for the rapid increase in temperature. Lightning strike emulatorwas employed for evaluating the response of copper electroless coatings on epoxy-CFRP laminates under these high demanding electrical events. Samples were coated for 15 and 30 min producing0.6 and 1.2 µm thick layers, respectively, and their performances were compared with commercially protected and naked laminates. Data show that a thin copper layer can improve the performance of CFRP under 40 kA discharges by absorbing part of the electrical energy, as a sacrificial protection. The surface of delaminated composite was lower whereas the coating area affected was larger for samples treated at longer times. An interesting relationship was found between the charge transfer and the damaged area, for all samples. In addition, sustained 30 A injection tests were performed and both electrical data and thermal imaging showed a better tolerance to continuous currents and a better heat dissipation of 30 min versus 15 min coated samples.